Novel shield pump reverse system of diesel hydrogenation device

Abstract

The utility model discloses a novel shield pump reverse system of a diesel hydrogenation device, which comprises a return tank, an air defense pipeline with a regulating valve is connected onto the return tank, and a first top reverse circulation line and a second top reverse circulation line are connected onto the air defense pipeline between the regulating valve and the return tank. The bottom of the return tank is connected with a first pipeline and a second pipeline, the first pipeline and the second pipeline are connected to the inlet end of the first shield pump and the inlet end of the second shield pump respectively, and the first top reverse circulation line and the second top reverse circulation line are connected to the upper ends of the first shield pump and the second shield pump respectively and then used for cooling. And stop valves are connected to the first pipeline, the second pipeline, the first top reverse circulation line and the second top reverse circulation line. The deethanization tower top reflux tank gas-phase pipeline anti-freezing device has the technical characteristics that the problems that the deethanization tower top reflux tank gas-phase pipeline is frozen for a long time, and the pressure is difficult to control can be solved.

Description

Technical Field

[0001] The utility model relates to a diesel fuel hydrogenation device shielded pump reverse system, more specifically, to a novel diesel fuel hydrogenation device shielded pump reverse system, belonging to the field of petrochemical industry. Background Art

[0002] The light hydrocarbon part of the diesel hydrocracking unit is mainly composed of a debutanizer, a deethanizer and a naphtha separation tower. A reflux tank and a reflux pump are installed on the top of the tower to provide reflux. The main component of the reflux of the deethanizer is a liquefied gas component containing a high concentration of hydrogen sulfide. In order to avoid leakage of high-concentration liquefied gas due to pump failure and endanger personal safety, a shielded pump is used for the reflux pump on the top of the deethanizer. The shielded pump is equipped with a reverse circulation line, which refluxes the medium to the inlet tank to achieve the purpose of cooling and lubricating the motor bearings and rotors. During the operation of the shielded pump, the valve of the reverse circulation line is normally open.

[0003] like Figure 1 As shown, the current reverse circulation line includes a reflux tank V-4004, and the reflux tank V-4004 is connected to a gas phase pipeline, and the gas phase pipeline is divided into a No. 1 top circulation loop line 01 and a No. 2 top circulation loop line 02, and the No. 1 top circulation loop line 01 and the No. 2 top circulation loop line 02 are respectively connected to a No. 1 shielded pump 03 and a No. 1 shielded pump 04, and the inlet ends of the No. 1 shielded pump 03 and the No. 1 shielded pump 04 are both connected to the bottom of the reflux tank V-4004. It can be seen from the existing reverse circulation line that it has the following problems:

[0004] 1. The reverse circulation line of the pump returns to the gas phase pipeline of the acid gas of the V-4004 reflux tank at the top of the deethanizer tower, which will cause frost on the back of the acid gas pipeline due to the gasification of liquefied gas, which may cause the risk of pipeline freezing and blocking, affecting the safe and stable operation of the device;

[0005] 2. There is a U-shaped bend between the No. 1 top circulation loop line 01 and the No. 2 top circulation loop line 02, which can easily cause condensate accumulation to form a "liquid seal" and affect the discharge of the gas phase. Utility Model Content

[0006] In order to solve the above-mentioned prior art problems, the utility model provides a novel diesel hydrogenation unit shielded pump reverse system having the technical characteristics of being able to avoid long-term freezing of the gas phase pipeline of the deethanizer top reflux tank and difficulty in controlling the pressure.

[0007] In order to achieve the above purpose, the utility model is implemented by the following technical solutions:

[0008] A novel diesel hydrogenation device shielded pump reverse system comprises a reflux tank, the reflux tank is connected to an air defense pipeline with a regulating valve, the air defense pipeline between the regulating valve and the reflux tank is connected to a No. 1 top reverse circulation line and a No. 2 top reverse circulation line, the bottom of the reflux tank is connected to a No. 1 pipeline and a No. 2 pipeline, the No. 1 pipeline and the No. 2 pipeline are respectively connected to the inlet ends of the No. 1 shielded pump and the No. 2 shielded pump, the No. 1 top reverse circulation line and the No. 2 top reverse circulation line are respectively connected to the upper ends of the No. 1 shielded pump and the No. 2 shielded pump for cooling, and the No. 1 pipeline, the No. 2 pipeline, the No. 1 top reverse circulation line and the No. 2 top reverse circulation line are all connected to stop valves.

[0009] Preferably, the No. 1 top reverse circulation line and the No. 2 top reverse circulation line are both connected to check valves, and the No. 1 top reverse circulation line and the No. 2 top reverse circulation line at the inlet end of the check valve are respectively connected to an external pipeline, and the external pipeline is connected to a stop valve.

[0010] Preferably, a gas phase outlet is provided on the left side of the upper end of the reflux tank, and the gas phase outlet is connected to a gas phase pipeline.

[0011] Preferably, an inlet is provided on the right side of the upper end of the reflux tank, and the inlet is connected to an inlet pipeline.

[0012] Beneficial effect: It avoids the problem of long-term freezing of the gas phase pipeline of the reflux tank at the top of the deethanizer tower and the difficulty in controlling the pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a reverse circulation line system diagram of a shielded pump in the prior art.

[0014] Figure 2 It is a schematic diagram of the utility model system. DETAILED DESCRIPTION

[0015] The present invention will be further described below in conjunction with the accompanying drawings, but the present invention is not limited to the following embodiments.

[0016] like Figure 2The figure shows a specific embodiment of a novel diesel hydrogenation device shielded pump reverse system, which is a novel diesel hydrogenation device shielded pump reverse system, including a reflux tank 1, the reflux tank 1 is connected to an air defense pipeline 2 with a regulating valve, the air defense pipeline 2 between the regulating valve and the reflux tank 1 is connected to a No. 1 top reverse circulation line 3 and a No. 2 top reverse circulation line 4, the bottom of the reflux tank 1 is connected to a No. 1 pipeline 5 and a No. 2 pipeline 6, the No. 1 pipeline 5 and the No. 2 pipeline 6 are respectively connected to the inlet ends of the No. 1 shielded pump 7 and the No. 2 shielded pump 8, the No. 1 top reverse circulation line 3 and the No. 2 top reverse circulation line 4 are respectively connected to the upper ends of the No. 1 shielded pump 7 and the No. 2 shielded pump 8, and the No. 1 pipeline 5, the No. 2 pipeline 6, the No. 1 top reverse circulation line 3, and the No. 2 top reverse circulation line 4 are all connected to stop valves. The No. 1 top reverse circulation line 3 and the No. 2 top reverse circulation line 4 are both connected to a check valve, and the No. 1 top reverse circulation line 3 and the No. 2 top reverse circulation line 4 at the inlet end of the check valve are respectively connected to an external pipeline, and the external pipeline is connected to a stop valve. A gas phase outlet is provided on the left side of the upper end of the reflux tank 1, and the gas phase outlet is connected to a gas phase pipeline 9. An inlet is provided on the right side of the upper end of the reflux tank 1, and the inlet is connected to an inlet pipeline 10.

[0017] Compared with the prior art, the present application changes the reverse circulation line from the gas phase of the reflux tank to the top of the reflux tank, and no U-bend is generated between the two shielded pumps in the newly set reverse circulation line. This avoids the freezing of the reverse circulation line liquid near the pressure control valve of the reflux tank 1 due to heat absorption during vaporization, and stabilizes the pressure of the reflux tank 1; the two shielded pumps each have a circulation line, which do not affect each other, and the U-bend is removed to avoid liquid sealing at the U-bend.

[0018] Technical requirements for installation of this application

[0019] 1. The dual-pump dual-circulation line design is adopted. The reverse circulation lines can be controlled separately during the process of starting, stopping and cutting the pump, and the dual pumps do not affect each other.

[0020] 2. The internal medium is liquefied gas before desulfurization, and the pipeline fittings are required to be resistant to high pressure and corrosion.

[0021] 3. When installing the pipeline, it can only be tilted horizontally and upwards, and no U-shaped bends are allowed.

[0022] Finally, it should be noted that the present invention is not limited to the above embodiments, and there are many variations. All variations that can be directly derived or associated with the content disclosed by ordinary technicians in this field should be considered as the protection scope of the present invention.

Claims

1. A new type of diesel hydrogenation unit canned pump reverse system, characterized by: The invention comprises a reflux tank (1), wherein the reflux tank (1) is connected to an air defense pipeline (2) with a regulating valve, the air defense pipeline (2) between the regulating valve and the reflux tank (1) is connected to a No. 1 top reverse circulation line (3) and a No. 2 top reverse circulation line (4), the bottom of the reflux tank (1) is connected to a No. 1 pipeline (5) and a No. 2 pipeline (6), the No. 1 pipeline (5) and the No. 2 pipeline (6) are respectively connected to the inlet ends of a No. 1 shielded pump (7) and a No. 2 shielded pump (8), the No. 1 top reverse circulation line (3) and the No. 2 top reverse circulation line (4) are respectively connected to the upper ends of the No. 1 shielded pump (7) and the No. 2 shielded pump (8), and the No. 1 pipeline (5), the No. 2 pipeline (6), the No. 1 top reverse circulation line (3) and the No. 2 top reverse circulation line (4) are all connected to stop valves.

2. According to claim 1, a novel diesel hydrogenation unit shielded pump reverse system is characterized by: The No. 1 top reverse circulation line (3) and the No. 2 top reverse circulation line (4) are both connected to a check valve, and the No. 1 top reverse circulation line (3) and the No. 2 top reverse circulation line (4) at the inlet end of the check valve are respectively connected to an external pipeline, and the external pipeline is connected to a stop valve.

3. According to claim 1 or a novel diesel hydrogenation unit shielded pump reverse system, it is characterized in that: A gas phase outlet is provided on the left side of the upper end of the reflux tank (1), and the gas phase outlet is connected to a gas phase pipeline (9).

4. A novel diesel hydrogenation unit canned pump reverse system according to claim 1 or 2, characterized in that: An inlet is provided on the right side of the upper end of the reflux tank (1), and the inlet is connected to an inlet pipeline (10).

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