Device for effectively controlling reforming sulfur injection amount

Abstract

The utility model discloses a device for effectively controlling reforming sulfur injection amount, which belongs to the technical field of petrochemical engineering, and comprises a tank body and a quantitative sulfur injection mechanism, the quantitative sulfur injection mechanism comprises a cylinder body, a piston plate is arranged in the cylinder body, a liquid inlet and a liquid outlet are arranged above the piston plate, the liquid inlet is connected with the cylinder body and the tank body, and the liquid outlet is connected with the tank body. Due to the fact that the sulfur injection amount is completely related to the stroke of the piston plate and the inner diameter of the cylinder body, the accuracy of the sulfur injection amount cannot be affected by conditions such as delayed feedback in the detection and electric control process, meanwhile, the cost is saved, and the problems that in the prior art, a sulfur injection control structure of the continuous reforming device is complex, and the sulfur injection amount cannot be accurately controlled are solved. And the cost is high.

Description

Technical Field

[0001] The utility model relates to the technical field of petrochemical industry, in particular to a device for effectively controlling the sulfur injection amount in reforming. Background Technique

[0002] Continuous reforming is a secondary oil processing technology. The processed raw materials are mainly straight-run naphtha with low octane number, hydrotreated naphtha, etc. Using a platinum Pt-rhenium Re bimetallic catalyst, at a high temperature of about 500 °C, the molecules are rearranged, isomerized, the output of aromatics is increased, and the octane number of gasoline is improved. The continuous reforming technology has the advantages of high aromatics yield, high liquid yield and high hydrogen yield. However, due to the relatively low operating pressure, high reaction temperature and low hydrogen / oil ratio in continuous reforming, the device is more likely to coke during the reaction process. Coking will cause poor catalyst flow, damage to the internal components of the reactor, and even lead to the shutdown of the device.

[0003] In order to prevent carbon deposition on the reactor wall and furnace tubes in the continuous reforming unit, a certain amount of dimethyl disulfide needs to be continuously injected into the system to ensure that there is about 0.5 ppm of hydrogen sulfide in the reforming recycle hydrogen, which can better prevent carbon penetration from forming an iron cap and squeezing and breaking the sector cylinder and the central tube. Since the injection amount of dimethyl disulfide is very small, controlling the sulfur injection amount has become a technical difficulty. Injecting too much will cause poisoning of the reforming catalyst and reduce the catalyst activity. Injecting too little is likely to cause carbon deposition on the walls and furnace tubes of the reaction device. In the prior art, the control structure for the sulfur injection amount is relatively complex.

[0004] For example, the "Method for Injecting Sulfur in a Continuous Reforming Unit" disclosed in the Chinese patent literature, with the publication number CN107434981A, includes replacing the reaction system filled with catalyst with a hydrogen-containing gas, raising the temperature to 300-480 °C, injecting sulfide into the pipeline between the reforming mixed feed heat exchanger and the feed heating furnace, and stopping the pre-sulfur injection when the sulfur content in the catalyst in the first reforming reactor is 100-200 μg / g or the H2S content in the recycle hydrogen is 2-4×10-6 L / L; after the reforming reaction is fed with materials, continue to inject sulfur into the feed pipeline of the continuous reforming unit. This patent discloses a method for injecting sulfur, which controls and adjusts the sulfur injection amount by monitoring the H2S content in the recycle hydrogen or the H2S content in the air discharged from the de-pentane tower, and requires more detection structures and electronic control structures, resulting in an increase in the device cost. Content of the Utility Model

[0005] The utility model is to overcome the problem that in the prior art, the structure for controlling sulfur injection in the continuous reforming unit is relatively complex, resulting in a high cost, and provides a device for effectively controlling the sulfur injection amount in reforming, which can effectively control the sulfur injection amount with a simpler structure, thereby reducing the cost.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] The utility model relates to a device for effectively controlling the sulfur injection amount in reforming, which comprises a tank body and a quantitative sulfur injection mechanism. The quantitative sulfur injection mechanism comprises a cylinder body, and a piston plate is installed inside the cylinder body. An inlet and a drain port are arranged above the piston plate. The inlet connects the cylinder body with the tank body, and the drain port connects the cylinder body with a drain pipe.

[0008] The control of the sulfur injection amount can be realized through the quantitative sulfur injection mechanism. When sulfur injection is required, the inlet is opened and the drain port is closed. Liquid enters the cylinder body and presses the piston plate. When the piston plate moves to the end of the stroke, the liquid above the piston plate is a fixed quantity. At this time, the drain port is opened and the inlet is closed to reset the piston plate, and quantitative sulfur injection can be achieved. Since the sulfur injection amount is completely related to the stroke of the piston plate and the inner diameter of the cylinder body, it will not affect the accuracy of the sulfur injection amount due to delay feedback in the detection and electronic control processes. At the same time, the cost is saved.

[0009] Preferably, a return spring is installed between the bottom of the cylinder body and the piston plate. The piston plate can be automatically reset through the return spring.

[0010] Preferably, a piston limiting rod penetrating inside and outside the cylinder body is installed at the bottom of the cylinder body. The moving position of the piston can be limited through the piston limiting rod, so as to ensure the accuracy of the liquid injection amount.

[0011] Preferably, the piston limiting rod is provided with an external thread, and a threaded hole adapted to the piston limiting rod is provided at the bottom of the cylinder body. This structure enables the piston limiting rod to be in an adjustable state, and the change of the sulfur injection amount can be controlled by adjusting the piston limiting rod.

[0012] Preferably, a contact switch is provided at the end of the piston limiting rod located inside the cylinder body. Through the contact switch, a signal can be generated when the piston limiting rod touches the piston plate, so as to control the opening and closing of the inlet and the drain port. This structure can reduce the duration of the sulfur injection action and thus improve the efficiency.

[0013] Preferably, the cylinder body is made of a transparent material, and scale lines are provided on the outer side of the cylinder body. Through this structure, when the operator adjusts the piston limiting rod, the adjustment can be made according to the scale lines, making the position of the piston limiting rod more accurate.

[0014] Preferably, a sealing ring is installed between the outer side of the piston plate and the cylinder body.

[0015] Preferably, a normally closed solenoid valve is installed at the inlet, and a normally open solenoid valve is installed at the drain port.

[0016] Preferably, a rotating plate is installed inside the cylinder body, and through holes are provided on the rotating plate. When the rotating plate rotates, the through holes can be aligned with the liquid inlet or the liquid outlet. When the through holes are aligned with the liquid inlet, the cylinder body is filled with liquid. When the through holes are aligned with the liquid outlet, the cylinder body is drained of liquid.

[0017] Preferably, a rotating plate driver for controlling the rotation of the rotating plate is installed above the cylinder body.

[0018] Therefore, the utility model has the following beneficial effects: (1) The sulfur injection amount can be effectively controlled with a simpler structure, thereby reducing costs; (2) The accuracy of the sulfur injection amount will not be affected by situations such as delayed feedback during detection and electro-control processes; (3) The sulfur injection amount can be accurately changed and adjusted. Description of the Drawings

[0019] Figure 1 is a schematic structural diagram of the utility model.

[0020] Figure 2 is a schematic structural diagram of Embodiment 1 of the utility model.

[0021] Figure 3 is a schematic internal structural diagram of Embodiment 1 of the utility model at the quantitative sulfur injection structure.

[0022] Figure 4 is a schematic internal structural diagram of Embodiment 2 of the utility model at the quantitative sulfur injection structure.

[0023] Figure 5 is a schematic internal structural diagram of Embodiment 3 of the utility model at the quantitative sulfur injection structure.

[0024] In the figure: tank body 1, adding port 2, charging pipe 3, support leg 4, cylinder body 5, piston plate 6, liquid inlet 7, liquid outlet 8, drain pipe 9, piston limiting rod 10, return spring 11, sealing ring 12, contact switch 13, rotating plate 14, rotating plate driver 15. Detailed Embodiments

[0025] The following further describes the utility model in conjunction with the drawings and specific embodiments.

[0026] Embodiment 1, as Figures 1 - 3 shown, a device for effectively controlling the sulfur injection amount during reforming includes a tank body 1 and a quantitative sulfur injection mechanism. An adding port 2 is provided at the inner top of the tank body 1, a charging pipe 3 is communicated with the inner top space of the tank body 1, and a plurality of support legs 4 are installed at the lower end of the tank body 1. A conical part is provided at the lower part of the tank body 1, and the conical part is used for collecting the liquid at the bottom space.

[0027] The quantitative sulfur injection mechanism includes a cylinder 5 fixedly connected to the lower end of the tank body 1, a piston plate 6 that can slide up and down is arranged in the cylinder 5, the lower end of the piston plate 6 is elastically connected to the inner bottom of the cylinder 5 through a return spring 11, and a liquid inlet 7 and a liquid discharge port 8 are arranged above the piston plate 6, the liquid inlet 7 connects the cylinder 5 and the tank body 1, and the liquid discharge port 8 connects the cylinder 5 and the liquid discharge pipe 9. The liquid discharge pipe 9 passes through the tank body 1 to introduce the discharged liquid into the subsequent reaction device. The outer ring of the piston plate 6 is installed with a sealing ring 12 for sealing with the cylinder 5. The sealing ring 12 is used to prevent the liquid above the piston plate 6 from entering the space below the piston plate 6 in the cylinder 5.

[0028] The cylinder 5 is also equipped with an adjustment mechanism, which includes a piston limit rod 10 installed at the bottom of the cylinder 5 and passing through the inside and outside of the cylinder 5. The piston limit rod 10 is provided with an external thread, and the bottom of the cylinder 5 is provided with a threaded hole adapted to the adjustment rod. The upper end surface of the piston limit rod 10 is used to abut the piston plate 6, so as to limit the piston plate 6. When the piston plate 6 moves downward to the piston limit rod 10, it stops moving, so that the liquid entering the cylinder 5 forms a fixed amount. After the piston plate 6 stops moving, the volume of the space between its upper side and the top of the cylinder 5 is the sulfur injection amount. The sulfur injection amount will not be affected by the delay of the electric control and detection, nor will it be affected by the opening and closing time of the liquid inlet 7 and the liquid discharge port 8, so the sulfur injection amount is more accurate. By twisting the piston limit rod 10, its vertical position can be adjusted. When the vertical position of the piston limit rod 10 changes, the distance from the piston plate 6 to the top of the cylinder 5 after the piston plate 6 moves to the end point will also change accordingly, so that the sulfur injection amount changes accordingly, and the sulfur injection amount can be reliably controlled. In this application, the sulfur injection amount should specifically be the distance that the piston plate 6 moves from the top position in the cylinder 5 to the piston limit rod 10 multiplied by the inner cross-sectional area of ​​the cylinder 5.

[0029] A normally closed solenoid valve is installed at the liquid inlet 7, and a normally open solenoid valve is installed at the liquid discharge port 8. The normally closed solenoid valve and the normally open solenoid valve are in the same series circuit, that is, when the normally closed solenoid valve is opened, the normally open solenoid valve is closed accordingly. The solenoid valves at the liquid inlet 7 and the liquid discharge port 8 are opened and closed according to the needs of sulfur injection. After the normally closed solenoid valve at the liquid inlet 7 is opened, it is necessary to wait for the liquid to press the piston plate 6 to the piston limit rod 10 before closing it. Although the solenoid valve is also used for electrical control in this embodiment, the delay of the electrical control and the length of time the solenoid valve is open will not affect the amount of sulfur injection.

[0030] The cylinder 5 is made of transparent material, and scale lines are arranged on the outside of the cylinder 5. Through this structure, when adjusting the piston limit rod 10, the operator can adjust it according to the scale lines, so that the position of the piston limit rod 10 is more accurate.

[0031] In the specific implementation process, when sulfur injection is required, the normally closed solenoid valve at the liquid inlet 7 is opened, and the normally open solenoid valve at the liquid outlet 8 is closed. Under the action of the liquid pressure in the tank 1, the liquid enters the cylinder 5 through the liquid inlet 7 and presses the piston plate 6 downward. While the piston plate 6 is being pressed downward, it drives the return spring 11 to compress. After the piston plate 6 is pressed downward by a certain distance, it contacts the piston limit rod 10 and thus stops moving further. At this time, although the liquid inlet 7 is still in the open state, the liquid will no longer enter the cylinder 5. At this time, the amount of liquid in the cylinder 5 is the sulfur injection amount. Then, the normally closed solenoid valve is closed, and the normally open solenoid valve is opened. Under the elastic force of the return spring 11, the piston plate 6 moves upward, and the liquid is discharged through the liquid outlet 8 into the drain pipe 9. When the piston plate 6 moves to the inner top of the cylinder 5, a sulfur injection action is completed.

[0032] Embodiment 2, as Figure 4 shown, a device for effectively controlling the sulfur injection amount of reforming includes a tank 1 and a quantitative sulfur injection mechanism. An addition port 2 is provided at the inner top of the tank 1. The space at the inner top of the tank 1 is communicated with a charging pipe 3. A plurality of support legs 4 are installed at the lower end of the tank 1. The lower part of the tank 1 is provided with a conical part, and the conical part is used for collecting the liquid at the bottom space.

[0033] The quantitative sulfur injection mechanism includes a cylinder 5 fixedly connected to the lower end of the tank 1. A piston plate 6 that can slide up and down is arranged in the cylinder 5. The lower end of the piston plate 6 is elastically connected to the inner bottom of the cylinder 5 through a return spring 11. An inlet 7 and an outlet 8 are provided above the piston plate 6. The inlet 7 connects the cylinder 5 and the tank 1, and the outlet 8 connects the cylinder 5 and the drain pipe 9. The drain pipe 9 passes through the tank 1 to introduce the discharged liquid into the subsequent reaction device. A sealing ring 12 for sealing with the cylinder 5 is installed on the outer ring of the piston plate 6. The sealing ring 12 is used to prevent the liquid above the piston plate 6 from entering the space below the piston plate 6 in the cylinder 5.

[0034] The cylinder 5 is also equipped with an adjustment mechanism, which includes a piston limit rod 10 installed at the bottom of the cylinder 5 and passing through the inside and outside of the cylinder 5. The piston limit rod 10 is provided with an external thread, and the bottom of the cylinder 5 is provided with a threaded hole adapted to the adjustment rod. The upper end surface of the piston limit rod 10 is used to abut the piston plate 6, so as to limit the piston plate 6. When the piston plate 6 moves downward to the piston limit rod 10, it stops moving, so that the liquid entering the cylinder 5 forms a fixed amount. After the piston plate 6 stops moving, the volume of the space between its upper side and the top of the cylinder 5 is the sulfur injection amount. The sulfur injection amount will not be affected by the delay of the electric control and detection, nor will it be affected by the opening and closing time of the liquid inlet 7 and the liquid discharge port 8, so the sulfur injection amount is more accurate. By twisting the piston limit rod 10, its vertical position can be adjusted. When the vertical position of the piston limit rod 10 changes, the distance from the piston plate 6 to the top of the cylinder 5 after the piston plate 6 moves to the end point will also change accordingly, so that the sulfur injection amount changes accordingly, and the sulfur injection amount can be reliably controlled. In this application, the sulfur injection amount should specifically be the distance that the piston plate 6 moves from the top position in the cylinder 5 to the piston limit rod 10 multiplied by the inner cross-sectional area of ​​the cylinder 5.

[0035] A contact switch 13 is provided on the end of the piston limit rod 10 located in the cylinder 5. The contact switch 13 can generate a signal when the piston limit rod 10 contacts the piston plate 6, thereby controlling the opening and closing of the liquid inlet 7 and the liquid outlet 8. This structure can reduce the duration of the sulfur injection action, thereby improving efficiency.

[0036] A normally closed solenoid valve is installed at the liquid inlet 7, and a normally open solenoid valve is installed at the liquid discharge port 8. The normally closed solenoid valve and the normally open solenoid valve are in the same series circuit, that is, when the normally closed solenoid valve is opened, the normally open solenoid valve is closed accordingly. The solenoid valves at the liquid inlet 7 and the liquid discharge port 8 are opened and closed according to the needs of sulfur injection. After the normally closed solenoid valve at the liquid inlet 7 is opened, it is necessary to wait for the liquid to press the piston plate 6 to the piston limit rod 10 before closing it. Although the solenoid valve is also used for electrical control in this embodiment, the delay of the electrical control and the length of time the solenoid valve is open will not affect the amount of sulfur injection.

[0037] The cylinder 5 is made of transparent material, and scale lines are arranged on the outside of the cylinder 5. Through this structure, when adjusting the piston limit rod 10, the operator can adjust it according to the scale lines, so that the position of the piston limit rod 10 is more accurate.

[0038] In the specific implementation process, when sulfur injection is required, the normally closed solenoid valve at the liquid inlet 7 is opened, and the normally open solenoid valve at the liquid outlet 8 is closed. Under the action of the liquid pressure in the tank body 1, the liquid enters the cylinder body 5 through the liquid inlet 7 and presses the piston plate 6 downward. While the piston plate 6 is pressed downward, it drives the return spring 11 to compress. After the piston plate 6 is pressed downward by a certain distance, it contacts the piston limit rod 10 and thus stops moving further. At this time, although the liquid inlet 7 is still in the open state, the liquid will no longer enter the cylinder body 5. At this time, the amount of liquid in the cylinder body 5 is the sulfur injection amount. Since the contact between the piston plate 6 and the contact switch 13 generates a signal, after the signal is transmitted to the controller, the normally closed solenoid valve is closed, and the normally open solenoid valve is opened. Under the elastic force of the return spring 11, the piston plate 6 moves upward, and the liquid is discharged through the liquid outlet 8 into the drain pipe 9. When the piston plate 6 moves to the inner top of the cylinder body 5, a sulfur injection action is completed.

[0039] Embodiment 3, as Figure 5 shown, a device for effectively controlling the sulfur injection amount in reforming includes a tank body 1 and a quantitative sulfur injection mechanism. An addition port 2 is provided at the inner top of the tank body 1. The space at the inner top of the tank body 1 is communicated with a charging pipe 3. A plurality of support legs 4 are installed at the lower end of the tank body 1. A conical part is provided at the lower part of the tank body 1, and the conical part is used to collect the liquid at the bottom space.

[0040] The quantitative sulfur injection mechanism includes a cylinder body 5 fixedly connected to the lower end of the tank body 1. A piston plate 6 that can slide up and down is arranged in the cylinder body 5. The lower end of the piston plate 6 is elastically connected to the inner bottom of the cylinder body 5 through a return spring 11. An inlet 7 and an outlet 8 are provided above the piston plate 6. The inlet 7 connects the cylinder body 5 and the tank body 1, and the outlet 8 connects the cylinder body 5 and the drain pipe 9. The drain pipe 9 passes through the tank body 1 to introduce the discharged liquid into the subsequent reaction device. A sealing ring 12 for sealing with the cylinder body 5 is installed on the outer ring of the piston plate 6. The sealing ring 12 is used to prevent the liquid above the piston plate 6 from entering the space below the piston plate 6 in the cylinder body 5.

[0041] An adjusting mechanism is also installed inside the cylinder body 5. The adjusting mechanism includes a piston limiting rod 10 installed at the bottom of the cylinder body 5 and penetrating through the inside and outside of the cylinder body 5. The piston limiting rod 10 is provided with an external thread, and a threaded hole adapted to the adjusting rod is provided at the bottom of the cylinder body 5. The upper end surface of the piston limiting rod 10 is used to abut against the piston plate 6 to limit the piston plate 6. When the piston plate 6 moves downward to the piston limiting rod 10, it stops moving, so that the liquid entering the cylinder body 5 forms a fixed quantity. After the piston plate 6 stops moving, the volume of the space between its upper side and the inner top of the cylinder body 5 is the sulfur injection quantity. This sulfur injection quantity is not affected by the delay of the electric control and detection, nor by the opening and closing time of the liquid inlet 7 and the liquid outlet 8. Therefore, the sulfur injection quantity is more accurate. By turning the piston limiting rod 10, its vertical position can be adjusted. When the vertical position of the piston limiting rod 10 changes, the distance between the piston plate 6 and the inner top of the cylinder body 5 after moving to the end point will also change correspondingly, so that the sulfur injection quantity changes correspondingly, and the sulfur injection quantity can be reliably controlled. In this application, the sulfur injection quantity should specifically be the distance that the piston plate 6 moves from the position of the inner top of the cylinder body 5 to the piston limiting rod 10 multiplied by the inner cross-sectional area of the cylinder body 5.

[0042] A rotating plate 14 is installed inside the cylinder body 5. The rotating plate 14 is provided with through holes. A rotating plate driver 15 for controlling the rotation of the rotating plate 14 is installed above the cylinder body 5. When the rotating plate 14 rotates, the through holes can be aligned with the liquid inlet 7 or the liquid outlet 8. When the through holes are aligned with the liquid inlet 7, the cylinder body 5 is filled with liquid. When the through holes are aligned with the liquid outlet 8, the cylinder body 5 is drained.

[0043] The cylinder body 5 is made of a transparent material, and scale lines are provided on the outside of the cylinder body 5. With this structure, when the operator adjusts the piston limiting rod 10, the adjustment can be made according to the scale lines, making the position of the piston limiting rod 10 more accurate.

[0044] In the specific implementation process, when sulfur injection is required, the rotating plate driver 15 is controlled by the controller to make the rotating plate 14 rotate, so that the through holes on the rotating plate 14 are aligned with the liquid inlet 7, making the liquid inlet 7 communicate with the inside of the cylinder body 5. Under the action of the liquid pressure in the tank body 1, the liquid enters the cylinder body 5 through the liquid inlet 7 and presses the piston plate 6 downward. While the piston plate 6 is being pressed downward, the return spring 11 is compressed. After the piston plate 6 is pressed downward by a certain distance, it contacts the piston limiting rod 10 and stops moving further. At this time, although the liquid inlet 7 is still in the open state, the liquid will no longer enter the cylinder body 5. At this time, the liquid volume in the cylinder body 5 is the sulfur injection quantity. At this time, the rotating plate driver 15 is controlled again to make the rotating plate 14 rotate, so that the through holes on the rotating plate 14 are aligned with the liquid outlet 8. Under the elastic force of the return spring 11, the piston plate 6 moves upward, and the liquid is discharged into the drain pipe 9 through the liquid outlet 8. When the piston plate 6 moves to the inner top of the cylinder body 5, a sulfur injection operation is completed.

Claims

1. A device for effectively controlling the amount of sulfur injection for reforming, characterized in that: It comprises a tank body and a quantitative sulfur injection mechanism, wherein the quantitative sulfur injection mechanism comprises a cylinder body, a piston plate is installed in the cylinder body, a liquid inlet and a liquid discharge port are arranged above the piston plate, the liquid inlet connects the cylinder body and the tank body, and the liquid discharge port connects the cylinder body and a liquid discharge pipe.

2. A device for effectively controlling the amount of sulfur injection during reforming according to claim 1, characterized in that: A return spring is installed between the bottom of the cylinder and the piston plate.

3. The device for effectively controlling the amount of sulfur injection during reforming according to claim 1, characterized in that: A piston limiting rod penetrating the inside and outside of the cylinder is installed at the bottom of the cylinder.

4. A device for effectively controlling the amount of sulfur injection for reforming according to claim 3, characterized in that: The piston limiting rod is provided with an external thread, and the bottom of the cylinder is provided with a threaded hole adapted to the piston limiting rod.

5. The device for effectively controlling the amount of sulfur injection during reforming according to claim 3, characterized in that: A contact switch is arranged on the end of the piston limiting rod located in the cylinder.

6. The device for effectively controlling the amount of sulfur injection during reforming according to claim 3, characterized in that: The cylinder is made of transparent material, and scale lines are arranged on the outside of the cylinder.

7. The device for effectively controlling the amount of sulfur injection during reforming according to claim 1, characterized in that: A sealing ring is installed between the outer side of the piston plate and the cylinder body.

8. A device for effectively controlling the amount of sulfur injection during reforming according to any one of claims 1 to 7, characterized in that: A normally closed solenoid valve is installed at the liquid inlet, and a normally open solenoid valve is installed at the liquid discharge port.

9. A device for effectively controlling the amount of sulfur injection during reforming according to any one of claims 1 to 7, characterized in that: A rotating plate is installed in the cylinder, and a through hole is provided on the rotating plate.

10. The device for effectively controlling the amount of sulfur injection during reforming according to claim 9, characterized in that: A rotating plate driver for controlling the rotation of the rotating plate is installed above the cylinder.

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