Vacuum tail gas pipeline anti-blocking and smoke elimination device for coking crude benzene hydrogenation equipment

Abstract

The present invention provides a vacuum tail gas pipeline anti-blocking and smoke elimination device for a coking crude benzene hydrogenation equipment, wherein the coking crude benzene hydrogenation equipment comprises a distillation tower, a tower top condenser, a reflux tank, a vacuum unit, a vacuum tail gas pipeline, a continuous liquid discharge liquid sealing device, and a flare, wherein the vacuum tail gas pipeline anti-blocking and smoke elimination device comprises a water washing tank and a gas-liquid separation tank, wherein the water washing tank is arranged on the inlet pipeline of the vacuum unit, between the reflux tank and the vacuum unit, and the gas-liquid separation tank is arranged between the vacuum tail gas pipeline and the continuous liquid discharge liquid sealing device. The vacuum tail gas pipeline anti-blocking and smoke elimination device of the present invention can effectively eliminate the smoke phenomenon caused by the blockage of the vacuum tail gas pipeline and the entrainment of benzene liquid, and realize the dual treatment of vacuum tail gas emission smoke and pipeline blockage.

Description

Technical Field

[0001] The invention belongs to the field of coking equipment and process technology, and specifically relates to a vacuum tail gas pipeline anti-blocking and smoke elimination device for coking crude benzene hydrogenation equipment, which is used to eliminate the blockage of the vacuum tail gas pipeline and the smoke phenomenon caused by the release and combustion of the vacuum tail gas. Background Art

[0002] Coking crude benzene hydrogenation equipment is the main equipment used in the coking crude benzene hydrogenation process. In the coking crude benzene hydrogenation process production line, the gas at the top of the distillation tower is condensed by the top condenser, and the condensed gas is extracted by the vacuum unit to form a vacuum tail gas mainly containing CS2, C5 and hydrocarbons below C5, salts, ash, benzene substances, etc. The vacuum tail gas is transported to the flare through the vacuum tail gas pipeline for dispersion and combustion.

[0003] In the prior art, a continuous drainage liquid sealing device is provided on the vacuum exhaust gas pipeline. During the operation of the vacuum unit, the vacuum exhaust gas temperature is 50-60°C (in summer) and 20-30°C (in winter) due to the heat generated by the operation of the vacuum unit. As the temperature drops, a large amount of benzene gas entrained during the transportation of the vacuum exhaust gas gradually turns into liquid phase. Although part of the liquid is continuously discharged through the continuous drainage liquid sealing device, it is not complete. The vacuum exhaust gas still carries a large amount of benzene liquid. When it enters the torch for combustion, smoke occurs, which does not meet the safety and environmental protection requirements.

[0004] On the other hand, the raw material crude benzene contains impurities, mainly ash and salts, which enter the vacuum tail gas from the top of the distillation tower along with the light component gas phase. After condensation in the top condenser, the vacuum tail gas temperature drops, the salt crystallizes, and the ash condenses around the crystals, gradually hardening and blocking the vacuum unit and vacuum tail gas pipeline, causing the vacuum tail gas pressure to increase frequently, the vacuum unit to shut down due to overload, and even production interruption.

[0005] Therefore, the vacuum tail gas pipeline of the coking crude benzene hydrogenation equipment in the prior art does not have any measures to prevent blockage, and due to the poor discharge effect of benzene liquid, it is difficult to suppress the flare emission and combustion smoke phenomenon. Summary of the invention

[0006] The object of the present invention is to overcome the above-mentioned deficiencies in the prior art, and for this purpose, a vacuum tail gas pipeline anti-blocking and smoke elimination device for a coking crude benzene hydrogenation equipment is provided, wherein the coking crude benzene hydrogenation equipment comprises a distillation tower, a tower top condenser, a reflux tank, a vacuum unit, a vacuum tail gas pipeline, a continuous liquid drainage and liquid sealing device, and a flare, wherein the vacuum tail gas pipeline anti-blocking and smoke elimination device comprises a water washing tank and a gas-liquid separation tank, wherein the water washing tank is arranged on the inlet pipeline of the vacuum unit, between the reflux tank and the vacuum unit, and the gas-liquid separation tank is arranged between the vacuum tail gas pipeline and the continuous liquid drainage and liquid sealing device.

[0007] Furthermore, in the vacuum tail gas pipeline anti-blocking and smoke elimination device of the above-mentioned coking crude benzene hydrogenation equipment, the water washing tank includes a condensate outlet arranged on the top of the tank, a condensate inlet arranged at the bottom of the tank, and an oil discharge outlet arranged at the top of the tank, the condensate outlet is connected to the vacuum unit through an outlet valve, the condensate inlet is connected to the reflux tank through an inlet valve, and the oil discharge outlet is connected to the reflux tank through a drain valve.

[0008] Furthermore, in the vacuum tail gas pipeline anti-blocking and smoke elimination device of the above-mentioned coking crude benzene hydrogenation equipment, the diameter of the gas-liquid separation tank is larger than the diameter of the vacuum tail gas pipeline.

[0009] Furthermore, in the vacuum tail gas pipeline anti-blocking and smoke elimination device of the above-mentioned coking crude benzene hydrogenation equipment, the diameter of the gas-liquid separation tank is 5 to 10 times the diameter of the vacuum tail gas pipeline.

[0010] Furthermore, in the vacuum tail gas pipeline anti-blocking and smoke elimination device of the above-mentioned coking crude benzene hydrogenation equipment, the water washing tank is set to two, including a first water washing tank and a second water washing tank, and a bypass valve is arranged in parallel with the first water washing tank and the second water washing tank, and the first water washing tank and the second water washing tank are one in operation and one in standby.

[0011] Furthermore, in the vacuum tail gas pipeline anti-blocking and smoke elimination device of the above-mentioned coking crude benzene hydrogenation equipment, the condensate outlet of the first water washing tank is connected to the vacuum unit through the first air outlet valve, the condensate inlet of the first water washing tank is connected to the reflux tank through the first air inlet valve, and the oil discharge outlet of the first water washing tank is connected to the reflux tank through the first liquid discharge valve; the condensate outlet of the second water washing tank is connected to the vacuum unit through the second air outlet valve, the condensate inlet of the second water washing tank is connected to the reflux tank through the second air inlet valve, and the oil discharge outlet of the second water washing tank is connected to the reflux tank through the second liquid discharge valve.

[0012] Furthermore, in the vacuum tail gas pipeline anti-blocking and smoke elimination device of the above-mentioned coking crude benzene hydrogenation equipment, the gas-liquid separation tank is connected to the vacuum tail gas pipeline through the gas-liquid separation tank inlet valve and the gas-liquid separation tank outlet valve, and the bottom of the gas-liquid separation tank is connected to the continuous drainage liquid seal device through the drain valve.

[0013] Furthermore, in the vacuum tail gas pipeline anti-blocking and smoke elimination device of the above-mentioned coking crude benzene hydrogenation equipment, the gas-liquid separation tank is provided with a bypass pipeline and a purge pipeline, the bypass pipeline is formed by a bypass valve arranged on the vacuum tail gas pipeline and between the gas-liquid separation tank inlet valve and the gas-liquid separation tank outlet valve, and the purge pipeline is composed of a steam valve and a nitrogen valve connected to the gas-liquid separation tank, corresponding steam sources and nitrogen sources, and pipelines.

[0014] Furthermore, the vacuum tail gas pipeline anti-blocking and smoke elimination device of the above-mentioned coking crude benzene hydrogenation equipment also includes a deep-cold water cooler arranged on the inlet pipeline of the vacuum unit, and the deep-cold water cooler maintains the temperature of the vacuum tail gas entering the vacuum unit below 20°C.

[0015] The vacuum tail gas pipeline anti-blocking and smoke elimination device of the coking crude benzene hydrogenation equipment of the present invention has at least the following beneficial effects: by arranging a water washing tank between the reflux tank and the vacuum unit and arranging a gas-liquid separation tank between the vacuum tail gas pipeline and the continuous liquid drainage liquid sealing device, the smoke phenomenon caused by the blockage of the vacuum tail gas pipeline and the entrainment of benzene liquid can be effectively eliminated, thereby realizing the dual control of vacuum tail gas emission smoke and pipeline blockage. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0017] Figure 1 The present invention is a schematic diagram of the structure of a vacuum tail gas pipeline anti-blocking and smoke elimination device of a coking crude benzene hydrogenation equipment according to an embodiment of the present invention.

[0018] Figure 2 It is a schematic diagram of the arrangement of a water washing tank in a vacuum tail gas pipeline anti-blocking and smoke elimination device of a coking crude benzene hydrogenation equipment in another embodiment of the present invention.

[0019] Figure 3 The present invention is a schematic diagram of the arrangement of a gas-liquid separation tank in a vacuum tail gas pipeline anti-blocking and smoke elimination device of a coking crude benzene hydrogenation equipment.

[0020] Description of reference numerals:

[0021] 1-distillation tower, 2-tower top condenser, 3-reflux tank, 4-vacuum unit, 5-vacuum tail gas pipeline, 6-continuous drainage liquid seal device, 7-torch;

[0022] 8-water washing tank, 80-air outlet valve, 81-air inlet valve, 82-liquid discharge valve;

[0023] 801-first water washing tank, 802-second water washing tank, 803-bypass valve, 810-first air outlet valve, 820-second air outlet valve, 811-first air inlet valve, 812-second air inlet valve, 821-first liquid discharge valve, 822-second liquid discharge valve;

[0024] 9-gas-liquid separation tank, 91-bypass valve, 92-gas-liquid separation tank inlet valve, 93-gas-liquid separation tank outlet valve, 94-drain valve, 95-steam valve, 96-nitrogen valve. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0026] Reference Figure 1 , shows a vacuum tail gas pipeline anti-blocking and smoke elimination device for a coking crude benzene hydrogenation equipment provided by an embodiment of the present invention, the coking crude benzene hydrogenation equipment comprises a distillation tower 1, a tower top condenser 2, a reflux tank 3, a vacuum unit 4, a vacuum tail gas pipeline 5, a continuous liquid drainage and liquid sealing device 6 and a flare 7, the top gas of the distillation tower 1 enters the reflux tank 3 after being condensed by the tower top condenser 2, the vacuum unit 4 extracts the condensed gas in the reflux tank 3 to form a vacuum tail gas, the vacuum tail gas enters the continuous liquid drainage and liquid sealing device 6 through the vacuum tail gas pipeline 5 for drainage, and then is transported to the flare 7 for dispersion and combustion, the condensate formed after the top gas of the distillation tower 1 is condensed by the tower top condenser 2 is collected in the reflux tank 3, wherein the vacuum tail gas pipeline anti-blocking and smoke elimination device comprises a water washing tank 8 and a gas-liquid separation tank 9, the water washing tank 8 is arranged on the inlet pipeline of the vacuum unit 4, and is located between the reflux tank 3 and the vacuum unit 4, and the gas-liquid separation tank 9 is arranged between the vacuum tail gas pipeline 5 and the continuous liquid drainage and liquid sealing device 6.

[0027] The water washing tank 8 includes a condensate outlet arranged on the tank top, a condensate inlet arranged at the bottom of the tank, and an oil discharge outlet arranged at the top of the tank. The condensate outlet is connected to the vacuum unit 4 through the air outlet valve 80, the condensate inlet is connected to the reflux tank 3 through the air inlet valve 81, and the oil discharge outlet is connected to the reflux tank 3 through the drain valve 82. Through the action of the vacuum unit 4, the condensate in the reflux tank 3 is extracted, and enters the water washing tank 8 from the condensate inlet at the bottom of the water washing tank 8 through the air inlet valve 81. After further water washing and cooling, the benzene gas is condensed into liquid oil. After gravity separation, the oil is discharged from the oil discharge outlet at the top of the water washing tank 8 to the reflux tank 3 through the drain valve 82. The gas is extracted from the water washing tank 8 through the air outlet valve 80 into the vacuum unit 4 to form vacuum tail gas, and the vacuum tail gas enters the vacuum tail gas pipeline 5. Therefore, after the condensed gas is washed with water, the benzene gas is cooled and collected at the source, reducing the entrainment of benzene gas in the vacuum exhaust gas and eliminating the subsequent formation of benzene liquid due to cooling of the benzene gas, which leads to smoke during the flare combustion.

[0028] In addition, the condensed gas is further washed and cooled by the water washing tank 8. By utilizing the solubility of salts and water, the impurities carried by the condensed gas are washed and dissolved, the salts remain in the water, and the ash falls to the bottom of the water washing tank 8, and thus will not enter the subsequent equipment. As a result, aggregation and hardening will no longer occur, greatly reducing the blockage of the vacuum exhaust gas pipeline.

[0029] The gas-liquid separation tank 9 is arranged between the vacuum tail gas pipeline 5 and the continuous liquid drainage and sealing device 6. The diameter of the gas-liquid separation tank 9 is much larger than the diameter of the vacuum tail gas pipeline 5. For example, the diameter of the gas-liquid separation tank 9 is 5 to 10 times the diameter of the vacuum tail gas pipeline 5. Therefore, before the vacuum tail gas enters the continuous liquid drainage and sealing device 6 for drainage and enters the flare 7, it first enters the gas-liquid separation tank 9, and after the buffering effect, the flow rate is reduced, and the liquid is fully separated. The liquid remains at the bottom of the gas-liquid separation tank 9, and then continuously drains through the continuous liquid drainage and sealing device 6, and the gas is discharged to the flare 7 through the vacuum tail gas pipeline 5.

[0030] Therefore, after being buffered by the gas-liquid separation tank 9, the gas and liquid are fully separated, and the benzene liquid entrained in the vacuum exhaust gas is eliminated. Since the gas and liquid are completely separated, the vacuum exhaust gas discharged to the flare 7 through the vacuum exhaust gas pipeline 5 no longer has any benzene liquid entrained, and enters the flare for dispersion and combustion. There will be no direct combustion of benzene in the liquid, which effectively solves the problem of combustion and smoke.

[0031] Reference Figure 2 , shows a vacuum tail gas pipeline anti-blocking and smoke elimination device for a coking crude benzene hydrogenation device provided by another embodiment of the present invention, Figure 2 The embodiment shown is in Figure 1 On the basis of the embodiment shown, the water washing tank 8 is set to two, namely the first water washing tank 801 and the second water washing tank 802, and a bypass valve 803 and a corresponding pipeline connected in parallel with the first water washing tank 801 and the second water washing tank 802 are provided to form a bypass pipeline. Through the first water washing tank 801 and the second water washing tank 802 being opened and reserved, the first water washing tank 801 and the second water washing tank 802 can be cleaned and replaced regularly to achieve continuous use. And in extreme cases, such as when the first water washing tank 801 and the second water washing tank 802 are both unusable, the bypass pipeline formed by the bypass valve 803 can still continue to realize the function of extracting condensed gas from the reflux tank 3 by the vacuum unit 4, thereby ensuring the normal operation of the coking crude benzene hydrogenation equipment.

[0032] exist Figure 2 In the embodiment shown, Figure 1Similar to the illustrated embodiment, the first water washing tank 801 and the second water washing tank 802 both include a condensate outlet arranged on the tank top, a condensate inlet arranged at the bottom of the tank, and an oil discharge outlet arranged at the top of the tank. The condensate outlet of the first water washing tank 801 is connected to the vacuum unit 4 through the first air outlet valve 810, the condensate inlet of the first water washing tank 801 is connected to the reflux tank 3 through the first air inlet valve 811, and the oil discharge outlet of the first water washing tank 801 is connected to the reflux tank 3 through the first liquid discharge valve 821; the condensate outlet of the second water washing tank 802 is connected to the vacuum unit 4 through the second air outlet valve 820, the condensate inlet of the second water washing tank 802 is connected to the reflux tank 3 through the second air inlet valve 812, and the oil discharge outlet of the second water washing tank 802 is connected to the reflux tank 3 through the second liquid discharge valve 822.

[0033] As a specific embodiment, in the vacuum tail gas pipeline anti-blocking and smoke elimination device of the coking crude benzene hydrogenation equipment of the present invention, as Figure 3 As shown, the gas-liquid separation tank 9 is arranged between the vacuum tail gas pipeline 5 and the continuous liquid discharge liquid sealing device 6 in the following manner: the gas-liquid separation tank 9 is connected to the vacuum tail gas pipeline 5 through the gas-liquid separation tank inlet valve 92 and the gas-liquid separation tank outlet valve 93, and the bottom of the gas-liquid separation tank 9 is connected to the continuous liquid discharge liquid sealing device 6 through the drain valve 94. The vacuum tail gas entering the vacuum tail gas pipeline 5 first enters the gas-liquid separation tank 9 through the gas-liquid separation tank inlet valve 92, and is fully separated from the liquid. The liquid remains at the bottom of the gas-liquid separation tank 9 and enters the continuous liquid discharge liquid sealing device 6 through the drain valve 94, and then is continuously discharged. The gas is discharged to the flare 7 through the vacuum tail gas pipeline 5 through the gas-liquid separation tank outlet valve 93.

[0034] Preferably, the gas-liquid separation tank 9 is also provided with a bypass pipeline and a purge pipeline for online cleaning and purging of the gas-liquid separation tank 9. Specifically, the bypass pipeline is formed by a bypass valve 91 disposed on the vacuum tail gas pipeline 5 and between the gas-liquid separation tank inlet valve 92 and the gas-liquid separation tank outlet valve 93, and the purge pipeline is composed of a steam valve 95 and a nitrogen valve 96 connected to the gas-liquid separation tank 9 and corresponding steam sources, nitrogen sources and pipelines. When the gas-liquid separation tank 9 needs to be cleaned and purged online, the bypass valve 91 is opened and connected, and steam and nitrogen are supplied to the gas-liquid separation tank 9 through the steam valve 95 and the nitrogen valve 96 to perform online cleaning and purging of the gas-liquid separation tank 9.

[0035] In addition, as a specific implementation method, in the vacuum exhaust gas pipeline anti-blocking and smoke elimination device of the coking crude benzene hydrogenation equipment of the present invention, a deep cold water cooler can also be set on the inlet pipeline of the vacuum unit 4 to keep the temperature of the vacuum exhaust gas entering the vacuum unit 4 below 20°C, thereby further enhancing the smoke elimination effect.

[0036] In summary, the vacuum tail gas pipeline anti-blocking and smoke elimination device of the coking crude benzene hydrogenation equipment of the present invention can effectively eliminate the smoke phenomenon caused by the blockage of the vacuum tail gas pipeline and the entrainment of benzene liquid by arranging a water washing tank between the reflux tank and the vacuum unit and a gas-liquid separation tank between the vacuum tail gas pipeline and the continuous liquid drainage liquid sealing device, thereby achieving dual control of vacuum tail gas smoke emission and pipeline blockage.

[0037] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In addition, "front", "back", "left", "right", "upper" and "lower" in this article are all referenced to the placement state shown in the accompanying drawings.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A vacuum tail gas pipeline anti-blocking and smoke elimination device for a coking crude benzene hydrogenation equipment, the coking crude benzene hydrogenation equipment comprising a distillation tower, a tower top condenser, a reflux tank, a vacuum unit, a vacuum tail gas pipeline, a continuous liquid drainage and liquid sealing device, and a torch, the vacuum tail gas pipeline anti-blocking and smoke elimination device comprising a water washing tank and a gas-liquid separation tank, the water washing tank is arranged on the inlet pipeline of the vacuum unit, located between the reflux tank and the vacuum unit, the gas-liquid separation tank is arranged between the vacuum tail gas pipeline and the continuous liquid drainage and liquid sealing device, characterized in that: The water washing tank comprises a condensate outlet arranged at the top of the tank, a condensate inlet arranged at the bottom of the tank, and an oil discharge outlet arranged at the top of the tank, wherein the condensate outlet is connected to the vacuum unit through an air outlet valve, the condensate inlet is connected to the reflux tank through an air inlet valve, and the oil discharge outlet is connected to the reflux tank through a liquid discharge valve; The gas-liquid separation tank is connected to the vacuum tail gas pipeline through a gas-liquid separation tank inlet valve and a gas-liquid separation tank outlet valve, and the bottom of the gas-liquid separation tank is connected to the continuous drainage liquid sealing device through a drainage valve.

2. The vacuum tail gas pipeline anti-blocking and smoke elimination device of the coking crude benzene hydrogenation equipment according to claim 1 is characterized in that: The diameter of the gas-liquid separation tank is greater than the diameter of the vacuum tail gas pipeline.

3. The vacuum tail gas pipeline anti-blocking and smoke elimination device of the coking crude benzene hydrogenation equipment according to claim 2 is characterized in that: The diameter of the gas-liquid separation tank is 5 to 10 times the diameter of the vacuum tail gas pipeline.

4. The vacuum tail gas pipeline anti-blocking and smoke elimination device of the coking crude benzene hydrogenation equipment according to claim 1 is characterized in that: The water washing tank is provided with two, including a first water washing tank and a second water washing tank, and a bypass valve is provided in parallel with the first water washing tank and the second water washing tank, and the first water washing tank and the second water washing tank are one in operation and one in standby.

5. The vacuum tail gas pipeline anti-blocking and smoke elimination device of the coking crude benzene hydrogenation equipment according to claim 4 is characterized in that: The condensate outlet of the first water washing tank is connected to the vacuum unit through the first air outlet valve, the condensate inlet of the first water washing tank is connected to the reflux tank through the first air inlet valve, and the oil discharge outlet of the first water washing tank is connected to the reflux tank through the first liquid discharge valve; the condensate outlet of the second water washing tank is connected to the vacuum unit through the second air outlet valve, the condensate inlet of the second water washing tank is connected to the reflux tank through the second air inlet valve, and the oil discharge outlet of the second water washing tank is connected to the reflux tank through the second liquid discharge valve.

6. The vacuum tail gas pipeline anti-blocking and smoke elimination device of the coking crude benzene hydrogenation equipment according to claim 1 is characterized in that: The gas-liquid separation tank is provided with a bypass pipeline and a purge pipeline. The bypass pipeline is formed by a bypass valve arranged on the vacuum tail gas pipeline and between the gas-liquid separation tank inlet valve and the gas-liquid separation tank outlet valve. The purge pipeline is composed of a steam valve and a nitrogen valve connected to the gas-liquid separation tank, corresponding steam sources and nitrogen sources, and pipelines.

7. The vacuum tail gas pipeline anti-blocking and smoke elimination device of the coking crude benzene hydrogenation equipment according to any one of claims 1 to 6, characterized in that: It also includes a deep-cold water cooler arranged on the inlet pipeline of the vacuum unit, and the deep-cold water cooler keeps the temperature of the vacuum tail gas entering the vacuum unit below 20°C.

Images