Device for preventing tail gas condensate of polyester device from flowing backwards

Abstract

The utility model discloses a device for preventing tail gas condensate of a polyester device from flowing backwards, which comprises a stripping tower connected with a polyester tail gas inlet pipe, an acetaldehyde recycle bin, a fan, a slurry tank, a tail gas blow-down pipe and an emptying valve, a feeding pipe is arranged between a gas inlet of the tail gas blow-down pipe and the stripping tower, and a stop valve is arranged at an outlet end of the feeding pipe. A feeding pipe is arranged in the slurry tank, a gas-liquid separator is arranged on the feeding pipe, a condensate discharging pipe is arranged on a liquid discharging port of the gas-liquid separator, a low-level collecting tank is arranged at the outlet end of the condensate discharging pipe and communicated with the rectifying position of the process tower, and a gas-liquid mixture flowing out of the slurry tank is subjected to gas-liquid separation through the gas-liquid separator and then is fed into the process tower. Gas containing a small amount of liquid is directly conveyed into the stripping tower through the feeding pipe for secondary condensate filtration, and the liquid enters the low-position collecting tank through the condensate discharge pipe for centralized treatment after being collected. The steam stripping tower can solve the problem that condensate flows backwards when the steam stripping tower carries out gas-liquid separation on polyester tail gas and slurry gas at the same time, and is easy and convenient to operate, remarkable in effect and convenient to maintain.

Description

TECHNICAL FIELD

[0001] The utility model relates to the device of preventing polyester device tail gas condensate backflow, specifically relates to a device of preventing polyester device tail gas condensate backflow. BACKGROUND

[0002] In the polyester melt direct spinning polyester production process for handling polyester excess tail gas, generally divided into two kinds, one is direct discharge, another is through the stripping tower gas-liquid separation, and the excess tail gas is transported to the central heating system by the fan and is incinerated, and the excess condensate is transported to the acetaldehyde recovery device for treatment by using the liquid level difference.

[0003] At present, in order to improve the environmental protection requirement, the company connects the discharged slurry tail gas into the gas tower for treatment, but in order to separate gas and liquid, according to the traditional treatment method, the gas tower is generally connected to the lower center position, but there is a problem that the condensate level of the stripping tower is often too high to cause the condensate to flow back into the system, which affects the production. In order to deal with such emergency situations, we have added an emergency discharge port for tail gas and condensate, which has achieved certain results, but still cannot completely avoid the influence of some condensate entering the system on production, so an urgent need exists for a device to solve this problem. SUMMARY

[0004] In order to solve the technical problems existing in the prior art, the purpose of the present application is to provide a device for preventing polyester device tail gas condensate backflow, which can solve the problem of condensate backflow when the stripping tower simultaneously separates gas and liquid for polyester tail gas and slurry gas, and has low improvement cost, simple operation, remarkable effect and convenient maintenance.

[0005] To solve the above technical problems, the present application adopts the following technical solutions:

[0006] The utility model provides a device for preventing the backflow of polyester device tail gas condensate, which comprises a stripping tower connected with a polyester tail gas inlet pipe, an acetaldehyde recovery station and a fan connected with the stripping tower through a pipeline, a slurry tank, a tail gas vent pipe provided on the slurry tank, and a vent valve provided on the tail gas vent pipe. The liquid filtered by the stripping tower enters the acetaldehyde recovery station for treatment, and the gas is discharged by the fan. The gas-liquid mixture in the slurry tank can open the vent valve to be directly discharged from the outer end of the tail gas vent pipe. A feeding pipe is provided between the gas inlet of the tail gas vent pipe and the stripping tower. A cut-off valve is provided at the outlet end of the feeding pipe. A gas-liquid separator is provided on the feeding pipe. A condensate discharge pipe is provided at the liquid discharge port of the gas-liquid separator. A low-position collection tank is provided at the outlet end of the condensate discharge pipe. The low-position collection tank is connected with a rectifying section of a process tower. After the gas-liquid mixture flowing out of the slurry tank is separated by the gas-liquid separator, the gas containing a small amount of liquid is directly conveyed to the stripping tower through the feeding pipe for secondary condensate filtration, and the liquid is collected in the low-position collection tank through the condensate discharge pipe for centralized treatment.

[0007] Preferably, an exhaust pipe is further provided between the feeding pipe and the gas inlet of the fan.

[0008] Preferably, a tail gas outlet valve is provided on the exhaust pipe.

[0009] Preferably, a pressure gauge is further provided on the exhaust pipe.

[0010] Preferably, a turnover liquid level meter is provided on one side of the stripping tower.

[0011] Preferably, a liquid level alarm is provided on the turnover liquid level meter.

[0012] Preferably, an inlet valve is provided at the inlet of the feeding pipe.

[0013] Preferably, an emergency liquid discharge pipe is further provided on the condensate discharge pipe, and a liquid discharge valve is provided on the emergency liquid discharge pipe.

[0014] Compared with the prior art, the utility model has the following beneficial effects:

[0015] In order to avoid the internal liquid overflow of the stripping tower after being connected with the gas-liquid mixture in the slurry tank, the gas-liquid separator is installed on the feeding pipe, the gas-liquid mixture in the slurry tank is separated by the gas-liquid separator first, most of the liquid can be discharged to the low-position collecting tank through the condensate discharge pipe on the liquid discharge port, and then is conveyed to the rectifying position of the process tower, and the gas containing a small amount of liquid in the slurry tank is directly conveyed to the stripping tower for secondary condensate filtration, the liquid is separated by the filtered gas-liquid, when the equipment is improved, the original device can be improved, and the online operation can be realized, the normal production is not affected, the improvement cost is low, the operation is simple, the maintenance is convenient, and the problem of the reverse flow of the polyester device tail gas condensate is solved. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is a structural schematic view of the utility model;

[0017] In the figure: 1, liquid discharge valve; 2, emergency liquid discharge pipe; 3, condensate discharge pipe; 4, slurry tank; 5, gas-liquid separator; 6, inlet valve; 7, vent valve; 8, tail gas vent pipe; 9, feeding pipe; 10, liquid level alarm; 11, cut-off valve; 12, exhaust pipe; 13, pressure gauge; 14, tail gas outlet valve; 15, fan; 16, stripping tower; 17, polyester tail gas inlet pipe; 18, flip liquid level meter; 19, acetaldehyde recovery station; 20, low-position collecting tank; 21, rectifying position of process tower. DETAILED DESCRIPTION

[0018] In the following, the application is further described in combination with the drawings and specific embodiments, and it should be noted that, under the condition of not conflicting, the following described embodiments or technical features can be combined to form new embodiments.

[0019] In the description of the application, it should be understood that the orientation or position relationship indicated by the terms "upper", "lower", "left", "right" and the like is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the application and simplifying the description, and does not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the application.

[0020] The terms "first", "second", and the like in the specification are used to distinguish between similar objects, and are not used to describe a particular sequential or chronological order. It should be understood that the data thus designated can be interchanged, where appropriate, so that the embodiments of the present application can be carried out in other than the order shown or described herein, and that the objects distinguished by "first", "second", etc. are generally of a class and are not limited in number, e.g. the first object can be one or more. In addition, "and / or" in the specification and claims means at least one of the connected objects, and the character " / ", generally means that the objects before and after it are in an "or" relationship.

[0021] As Figure 1 shown, a device for preventing the backflow of polyester device tail gas condensate, comprising a stripping tower 16 connected with the polyester tail gas inlet pipe 17, an acetaldehyde recovery station 19 and a fan 15 connected with the stripping tower 16 through a pipeline, a slurry tank 4, a tail gas vent pipe 8 provided on the slurry tank 4, and a vent valve 7 provided on the tail gas vent pipe 8. The liquid filtered by the stripping tower 16 enters the acetaldehyde recovery station 19 for treatment, and the gas is discharged through the fan 15. The gas-liquid mixture in the slurry tank 4 can open the vent valve 7 to directly discharge from the outer end of the tail gas vent pipe 8. A feeding pipe 9 is provided between the gas inlet of the tail gas vent pipe 8 and the stripping tower 16. A cut-off valve 11 is provided at the outlet end of the feeding pipe 9. A gas-liquid separator 5 is provided on the feeding pipe 9. A condensate discharge pipe 3 is provided at the liquid outlet of the gas-liquid separator 5. A low-position collection tank 20 is provided at the outlet end of the condensate discharge pipe 3. The low-position collection tank 20 is in communication with a process tower rectification position 21. After the gas-liquid mixture flowing out of the slurry tank 4 is subjected to gas-liquid separation by the gas-liquid separator 5, the gas containing a small amount of liquid is directly conveyed to the stripping tower 16 through the feeding pipe 9 for secondary condensate filtration, and the liquid is collected in the low-position collection tank 20 through the condensate discharge pipe 3 for centralized treatment.

[0022] In actual use, the polyester tail gas enters the stripping tower 16 through the polyester tail gas inlet pipe 17, and the gas-liquid mixture discharged from the slurry tank 4 enters the stripping tower 16 through the feeding pipe 9 after the vent valve 7 is closed and the cut-off valve 11 is opened for gas-liquid separation, and then enters the acetaldehyde recovery station 19 for treatment, and the gas is discharged by the fan 15. In order to avoid the internal liquid overflow of the stripping tower 16 after the gas-liquid mixture in the slurry tank 4 is connected, a gas-liquid separator 5 is installed on the feeding pipe 9, and the gas-liquid mixture in the slurry tank 4 is first separated by the gas-liquid separator 5, so that most of the liquid can be discharged into the low-position collection tank 20 through the condensate discharge pipe 3 on the liquid discharge port, and then transported to the process tower rectification position 21 for connection, and the gas containing a small amount of liquid in the slurry tank 4 is directly transported into the stripping tower 16 through the feeding pipe 9 for secondary condensate filtration, and the liquid is separated and treated after the filtered gas-liquid is separated. When improving the equipment, the original device can be improved, and online operation can be performed without affecting normal production, the improvement cost is low, the operation is simple, the maintenance is convenient, and the problem of polyester device tail gas condensate backflow is effectively solved.

[0023] Further improvement is that the feeding pipe 9 and the fan 15 inlet are further provided with an exhaust pipe 12.

[0024] An exhaust pipe 12 is added between the feeding pipe 9 and the fan 15 inlet, and the gas treated by the gas-liquid separator can be directly discharged to the outside through the fan 15 through the exhaust pipe 12, so that the problem that the gas-liquid separator 5 cannot be cut off when the liquid level of the stripping tower 16 is too high, and the gas-liquid separator 5 cannot be cut off after the gas-liquid separator 5 is cut off.

[0025] Further improvement is that the exhaust pipe 12 is provided with a tail gas outlet valve 14; and the exhaust pipe 12 is further provided with a pressure gauge 13.

[0026] The tail gas outlet valve 14 and the pressure gauge 13 are installed on the exhaust pipe 12, the gas after the gas-liquid separation can be discharged more flexibly through the tail gas outlet valve 14, and at the same time, the opening and closing control of the tail gas outlet valve 14 can be realized through the pressure gauge 13, so that the problem of excessive internal pipeline pressure is avoided.

[0027] Further improvement is that the stripping tower 16 is provided with a flip liquid level meter 18 on one side; and the flip liquid level meter 18 is provided with a liquid level alarm 10.

[0028] A flip-over liquid level gauge 18 is installed on one side of the stripping tower 16, which can directly observe the liquid level in the stripping tower 16. When the liquid level is too high, the exhaust gas outlet valve 14 can be opened to exhaust gas, so as to avoid the situation of backflow caused by too high liquid level. After being connected with the central control DCS system, 24-hour computer monitoring and alarm of the liquid level can be realized, so as to avoid the problem of not timely finding out the too high liquid level.

[0029] According to the change of the condensate liquid level in the stripping tower 16 and the tail gas pressure, a set of liquid level alarm device is installed on the pipeline connecting the original slurry tail gas pipeline and the stripping tower 16. By setting the liquid level alarm point and the pressure alarm point, 24-hour computer monitoring can be realized by connecting the central control DCS system, so as to find out the abnormality in advance and effectively avoid the situation of condensate backflow. The device can be online modified, has low cost and does not affect the normal production of the device.

[0030] Further improvement is that the feeding port of the feeding pipe 9 is provided with an inlet valve 6.

[0031] Before installation, the vent valve 7 is first opened, the cut-off valve 11 and the inlet valve 6 connected to the central lower position of the stripping tower 16 are closed, then a gas-liquid separator 5 is newly added at the low point of the feeding pipe 9, one end of which is connected to the inlet of the tail gas vent pipe 8, and the other end is connected to the inlet of the fan 15. The gas-liquid separator 5 is provided with a condensate discharge pipe 3 at the bottom, one end of which is connected to the low-position collection tank 20 for daily condensate collection and then transported to the process tower for rectification treatment. Finally, according to the change of the condensate liquid level in the stripping tower 16 and the tail gas pressure, a flip-over liquid level gauge 18 with a liquid level alarm 10 is installed on the pipeline connecting the original slurry tail gas pipeline and the stripping tower 16, and a pressure gauge 13 and a tail gas outlet valve 14 are installed at the gas outlet end of the exhaust pipe 12. By setting the liquid level alarm point and the pressure alarm point, 24-hour computer monitoring can be realized by connecting the central control DCS system, so as to completely solve the problem of condensate backflow of the tail gas of the polyester device.

[0032] Further improvement is that the condensate discharge pipe 3 is further provided with an emergency liquid discharge pipe 2, and the emergency liquid discharge pipe 2 is provided with a liquid discharge valve 1.

[0033] In order to realize emergency liquid discharge of the gas-liquid separator 5 and avoid liquid blockage and overflow, an emergency liquid discharge pipe 2 with a liquid discharge valve 1 is added to the condensate discharge pipe 3. When the low-position collection tank 20 cannot timely discharge liquid or the condensate discharge pipe 3 is blocked, the liquid discharge valve 1 can be temporarily opened for emergency liquid discharge.

[0034] The above embodiments are only preferred embodiments of the present application, and cannot be used to limit the scope of protection of the present application. Any non-essential changes and replacements made by those skilled in the art on the basis of the present application shall fall within the scope of protection of the present application.

Claims

1. A device for preventing backflow of polyester plant tail gas condensate, comprising a stripping tower (16) connected with a polyester tail gas inlet pipe (17), an acetaldehyde recovery station (19) and a fan (15) connected with the stripping tower (16) through a pipeline, a slurry tank (4), a tail gas vent pipe (8) provided on the slurry tank (4), and a vent valve (7) provided on the tail gas vent pipe (8), wherein the liquid filtered by the stripping tower (16) enters the acetaldehyde recovery station (19) for treatment, and the gas is discharged through the fan (15), and the gas-liquid mixture in the slurry tank (4) can directly discharge from the outer end of the tail gas vent pipe (8) by opening the vent valve (7), characterized in that: The tail gas vent pipe (8) is provided with a feeding pipe (9) between the gas inlet and the stripping tower (16), the outlet end of the feeding pipe (9) is provided with a cut-off valve (11), the feeding pipe (9) is provided with a gas-liquid separator (5), the gas-liquid separator (5) is provided with a condensate discharge pipe (3) at the liquid discharge port, the outlet end of the condensate discharge pipe (3) is provided with a low-position collecting tank (20), the low-position collecting tank (20) is communicated with a process tower rectification position (21), after the gas-liquid mixture flowing out of the slurry tank (4) is separated by the gas-liquid separator (5), the gas containing a small amount of liquid is directly transported into the stripping tower (16) through the feeding pipe (9) to be filtered for the second time, and the liquid is collected into the low-position collecting tank (20) through the condensate discharge pipe (3) to be treated.

2. The device for preventing the reverse flow of the condensed liquid of the exhaust gas of the polyester device according to claim 1, characterized in that: The feeding pipe (9) is further provided with an exhaust pipe (12) between the gas inlet and the fan (15).

3. The device for preventing the backflow of the condensed liquid of the exhaust gas of the polyester device according to claim 2, characterized in that: The exhaust pipe (12) is provided with a tail gas outlet valve (14).

4. The device for preventing the reverse flow of the condensed liquid of the exhaust gas of the polyester plant according to claim 3, characterized in that: The exhaust pipe (12) is further provided with a pressure gauge (13).

5. The device for preventing the backflow of the condensed liquid of the exhaust gas of the polyester device according to claim 4, characterized in that: One side of the stripping tower (16) is provided with a turnover liquid level meter (18).

6. The device for preventing the backflow of the condensed liquid of the exhaust gas of the polyester device according to claim 5, characterized in that: The turnover liquid level meter (18) is provided with a liquid level alarm (10).

7. A device for preventing backflow of condensate from the exhaust of a polyester plant according to any one of claims 1 to 6, characterized in that: The feeding pipe (9) is provided with an inlet valve (6) at the feeding port.

8. The device for preventing the backflow of the condensed liquid of the exhaust gas of the polyester device according to claim 1, characterized in that: The condensate discharge pipe (3) is further provided with an emergency liquid discharge pipe (2), and the emergency liquid discharge pipe (2) is provided with a liquid discharge valve (1).

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