1. A system for extracting at the top of an industrial naphthalene rectifying tower and emptying a safety valve is characterized by comprising an industrial naphthalene rectifying tower, an industrial naphthalene/raw material heat exchanger, an industrial naphthalene vaporization water-cooling condensation cooler, an industrial naphthalene vaporization air-cooling condensation cooler and an industrial naphthalene reflux tank; the outlet pipeline of the industrial naphthalene rectifying tower is divided into two paths after passing through an industrial naphthalene/raw material heat exchanger, one path is connected with the inlet pipeline of an industrial naphthalene vaporization water-cooling condensation cooler, and the other path is connected with the inlet pipeline of the industrial naphthalene vaporization air-cooling condensation cooler through a throttling plate; the discharge pipeline of the safety valve of the industrial naphthalene rectifying tower is connected with the inlet pipeline of the industrial naphthalene vaporization air-cooling condensation cooler; an outlet pipeline of the industrial naphthalene vaporization water-cooling condensation cooler is joined with an outlet pipeline of the industrial naphthalene vaporization air-cooling condensation cooler and then is connected with an inlet pipeline of an industrial naphthalene reflux tank, and an outlet pipeline of the industrial naphthalene reflux tank is connected with an industrial naphthalene rectifying tower.

2. The system for extracting from the top of the industrial naphthalene rectification column and emptying the safety valve as claimed in claim 1, further comprising a first valve, wherein the first valve is installed on an outlet pipeline of the industrial naphthalene rectification column.

3. The system for extracting and emptying the top of the industrial naphthalene rectifying tower and the safety valve as claimed in claim 1, further comprising a second valve, wherein one end of the second valve is connected with an outlet pipeline of the industrial naphthalene rectifying tower through a pipeline, and the other end of the second valve is connected with an inlet pipeline of the industrial naphthalene vaporization air-cooling condensation cooler through a pipeline.

4. The system for extracting and venting the safety valve at the top of the industrial naphthalene rectification tower according to claim 1, further comprising a reflux pump, wherein the reflux pump is installed on an outlet pipeline of the industrial naphthalene reflux tank.

5. A process based on the system for extracting and emptying the safety valve at the top of the industrial naphthalene rectifying tower according to any one of claims 1 to 4 is characterized by comprising the following steps:

1) the industrial naphthalene vapor is cooled by an industrial naphthalene vaporization water-cooling condensation cooler and an industrial naphthalene vaporization air-cooling condensation cooler which are connected in parallel, most of the industrial naphthalene vapor adopts the industrial naphthalene vaporization water-cooling condensation cooler, and a small part of the industrial naphthalene vaporization air-cooling condensation cooler is used for maintaining the water temperature of the industrial naphthalene in the industrial naphthalene condensation cooler at the lower part of the industrial naphthalene vaporization air-cooling condensation cooler, so that the temperature of the industrial naphthalene is kept at 80-100 ℃, and the industrial naphthalene vaporization air-cooling condensation cooler is convenient to use when a safety valve is used for emergency emptying;

2) the industrial naphthalene vaporization air-cooling condensation cooler ensures the whole discharge amount of cooling when the safety valve is in emergency emptying;

3) the industrial naphthalene vapor amount cooled by the industrial naphthalene vaporization air-cooling condensation cooler is controlled by a throttle orifice, when cold seasons come, the treatment capacity of equipment is improved by controlling a valve, and all or part of the equipment is cooled by the industrial naphthalene vaporization air-cooling condensation cooler;

4) when the industrial naphthalene rectifying tower is over-pressurized, the industrial naphthalene can be cooled by an industrial naphthalene vaporization air cooling condensation cooler.

Background

Naphthalene is a main product processed from coal tar, accounts for about 10-12% of the coal tar, belongs to an important organic chemical basic raw material, and is widely used for producing products such as dyes, medicines and the like. The naphthalene produced by the coal tar comprises industrial naphthalene and refined naphthalene, the crystallization point of the industrial naphthalene is not less than 78 ℃, the naphthalene content is not less than 95%, the crystallization point of the refined naphthalene is not less than 79-6 ℃, and the naphthalene content of the refined naphthalene is not less than 99%. The separation and the refining of the naphthalene are important links in the coal tar processing and are also important ways for obtaining the naphthalene. In the current production, industrial naphthalene distillation is the conventional method for producing industrial naphthalene.

The industrial naphthalene distillation is divided into three process routes of reduced pressure distillation, atmospheric distillation and pressurized distillation, the atmospheric pressure process also comprises a single-furnace single-tower process, a single-furnace double-tower process and a double-furnace double-tower process, and as the crystallization point of the industrial naphthalene is not less than 78 ℃, in order to prevent the industrial naphthalene from generating crystallization in the cooling process, an industrial naphthalene vaporization condensation cooler is usually selected as a cooling device for industrial naphthalene products.

The industrial naphthalene vaporization condensation cooler is composed of two parts, wherein the upper part is a water vapor condensation cooler, the lower part is an industrial naphthalene condensation cooler, water is heated and vaporized in the cooling process of the lower part of the industrial naphthalene, the water vapor enters the water vapor condensation cooler on the upper part and is condensed and cooled into condensate by circulating water, and the condensate returns to the lower part to form closed circulation of the water and the water vapor, and the industrial naphthalene is cooled by hot water equivalently and cannot be crystallized to cause blockage.

CN112595133A discloses "an industrial naphthalene vaporization condensation cooler and its working method", which is an industrial naphthalene vaporization air cooling condensation cooler, the principle is similar to the above industrial naphthalene vaporization condensation cooler, but the vaporized water vapor is cooled by air instead of by circulating water.

The process flow of the normal-pressure single furnace or double furnaces and double towers is as follows: the raw material tertiary mixed fraction is sent to an industrial naphthalene/raw material heat exchanger by a raw material pump, exchanges heat with industrial naphthalene vapor coming out of the top of an industrial naphthalene rectifying tower and then enters a technical naphthalene primary distillation tower; after phenol oil steam escaping from the top of the primary tower is cooled by a condensing cooler, separating phenol oil by an oil-water separator and feeding the phenol oil into a phenol oil reflux tank; one part is used for refluxing to control the temperature of the top of the primary distillation tower, and the rest is sent to a phenol oil tank; most of the bottom fraction is sent to a tubular furnace for heating, and then returned to the bottom evaporation section of the primary distillation tower, so that heat is circularly supplied to the primary distillation tower, and a small part of the bottom fraction is sent to an industrial naphthalene rectification tower. Industrial naphthalene vapor discharged from the top of the industrial naphthalene rectifying tower is subjected to heat exchange with a raw material of a primary distillation tower through an industrial naphthalene/raw material heat exchanger, then is sent to an industrial naphthalene vaporization and condensation cooler, is cooled and then is sent to an industrial naphthalene reflux tank, most of the industrial naphthalene vapor is used for reflux to control the temperature of the top of the rectifying tower, and the rest industrial naphthalene vapor is sent to an industrial naphthalene overhead tank; most of the bottom fraction is sent to a tube furnace for heating and then returned to the bottom evaporation section of the primary tower, so that heat is supplied to the primary tower circularly, and a small part of the bottom fraction is sent to an external oil washing tank.

The safety protection of the No. 6 part GB/T20801-2006 Industrial pipeline Specification: "the gas phase pipeline at the top of the distillation tower which is overpressured due to the interruption of cooling water or reflux or excessive heat input by the reboiler is provided with a safe relief device". Therefore, in the distillation tower top of the existing tar processing and deep processing device, safety valves are arranged on the tower top or a gas phase pipeline in a new design, wherein the safety valves comprise the tower top of an industrial naphthalene rectifying tower and other tower top safety valves, and the safety valves are air-cooled and then discharged into a vent tank (see CN109806716A, which discloses a safety valve emergency venting system in the coking production process), but the safety valves on the tower top of the industrial naphthalene rectifying tower cannot adopt the operation mode, because the industrial naphthalene can be crystallized after air cooling and can block the pipeline and equipment.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides a process for extracting at the top of an industrial naphthalene rectifying tower and emptying a safety valve, which is not only used when the safety valve is emergently emptied, but also can replace or partially replace an industrial naphthalene vaporization condensation cooler cooled by circulating water in cold seasons, thereby saving energy and being safe, and achieving the aim of bringing out the best in the process design and the safety design.

In order to achieve the purpose, the invention adopts the following technical scheme:

a system for extracting at the top of an industrial naphthalene rectifying tower and emptying a safety valve comprises an industrial naphthalene rectifying tower, an industrial naphthalene/raw material heat exchanger, an industrial naphthalene vaporization water-cooling condensation cooler, an industrial naphthalene vaporization air-cooling condensation cooler and an industrial naphthalene reflux tank; the outlet pipeline of the industrial naphthalene rectifying tower is divided into two paths after passing through an industrial naphthalene/raw material heat exchanger, one path is connected with the inlet pipeline of an industrial naphthalene vaporization water-cooling condensation cooler, and the other path is connected with the inlet pipeline of the industrial naphthalene vaporization air-cooling condensation cooler through a throttling plate; the discharge pipeline of the safety valve of the industrial naphthalene rectifying tower is connected with the inlet pipeline of the industrial naphthalene vaporization air-cooling condensation cooler; an outlet pipeline of the industrial naphthalene vaporization water-cooling condensation cooler is joined with an outlet pipeline of the industrial naphthalene vaporization air-cooling condensation cooler and then is connected with an inlet pipeline of an industrial naphthalene reflux tank, and an outlet pipeline of the industrial naphthalene reflux tank is connected with an industrial naphthalene rectifying tower.

The industrial naphthalene rectifying tower further comprises a first valve, and the first valve is installed on an outlet pipeline of the industrial naphthalene rectifying tower.

One end of the second valve is connected with an outlet pipeline of the industrial naphthalene rectifying tower through a pipeline, and the other end of the second valve is connected with an inlet pipeline of the industrial naphthalene vaporization air-cooling condensation cooler through a pipeline.

The system also comprises a reflux pump, and the reflux pump is arranged on an outlet pipeline of the industrial naphthalene reflux tank.

A process for extracting and emptying a safety valve at the top of an industrial naphthalene rectifying tower specifically comprises the following steps:

1) the industrial naphthalene vapor is cooled by an industrial naphthalene vaporization water-cooling condensation cooler and an industrial naphthalene vaporization air-cooling condensation cooler which are connected in parallel, most of the industrial naphthalene vapor adopts the industrial naphthalene vaporization water-cooling condensation cooler, and a small part of the industrial naphthalene vaporization air-cooling condensation cooler is used for maintaining the water temperature of the industrial naphthalene in the industrial naphthalene condensation cooler at the lower part of the industrial naphthalene vaporization air-cooling condensation cooler, so that the temperature of the industrial naphthalene is kept at 80-100 ℃, and the industrial naphthalene vaporization air-cooling condensation cooler is convenient to use when a safety valve is used for emergency emptying;

2) the industrial naphthalene vaporization air-cooling condensation cooler ensures the whole discharge amount of cooling when the safety valve is in emergency emptying;

3) the industrial naphthalene vapor amount cooled by the industrial naphthalene vaporization air-cooling condensation cooler is controlled by a throttle orifice, when cold seasons come, the treatment capacity of equipment is improved by controlling a valve, and all or part of the equipment is cooled by the industrial naphthalene vaporization air-cooling condensation cooler;

4) when the industrial naphthalene rectifying tower is over-pressurized, the industrial naphthalene can be cooled by an industrial naphthalene vaporization air cooling condensation cooler.

Compared with the prior art, the invention has the beneficial effects that:

1) the industrial naphthalene vapor is cooled by an industrial naphthalene vaporization water-cooling condensation cooler and an industrial naphthalene vaporization air-cooling condensation cooler which are connected in parallel, most of the industrial naphthalene vapor adopts the industrial naphthalene vaporization water-cooling condensation cooler, and a small part of the industrial naphthalene vaporization air-cooling condensation cooler is used for maintaining the water temperature of the industrial naphthalene at the lower part of the industrial naphthalene vaporization air-cooling condensation cooler to be 80-100 ℃, so that the industrial naphthalene vaporization air-cooling condensation cooler is convenient to use when a safety valve is used for emergency emptying.

2) The industrial naphthalene vapor amount cooled by the industrial naphthalene vaporization air-cooling condensation cooler is controlled by the throttle orifice, the treatment capacity of equipment can be improved by a traffic pipe valve when cold seasons come, and the industrial naphthalene vaporization air-cooling condensation cooler can be wholly or partially used for cooling, so that energy is saved and safety is realized.

3) The safety valve discharge pipeline on the top of the industrial naphthalene rectifying tower is connected with the industrial naphthalene steam inlet pipeline of the industrial naphthalene vaporization air-cooling condensation cooler, and the industrial naphthalene vaporization air-cooling condensation cooler can play a cooling role when the cooling water or reflux is interrupted or the reboiler inputs too much heat to cause the overpressure of the industrial naphthalene rectifying tower.

The industrial naphthalene vaporization air-cooling condensation cooler is introduced as an alternative cooler for the industrial naphthalene vapor, and the industrial naphthalene vaporization air-cooling condensation cooler is selected to replace an air condensation cooler or a circulating water cooler, so that the industrial naphthalene vapor is prevented from generating crystallization to block a pipeline during cooling, and the industrial naphthalene vaporization air-cooling condensation cooler is energy-saving and safe.

Drawings

FIG. 1 is a schematic diagram of the structure and process of the present invention.

In the figure: 1-industrial naphthalene rectifying tower 2-industrial naphthalene/raw material heat exchanger 3-industrial naphthalene vaporization water-cooling condensation cooler 4-industrial naphthalene vaporization air-cooling condensation cooler 5-industrial naphthalene reflux tank 6-industrial naphthalene reflux pump 7-safety valve 8-first valve 9-second valve 10-orifice plate

Detailed Description

The following further describes embodiments of the present invention with reference to the accompanying drawings:

as shown in fig. 1, a system for extracting at the top of an industrial naphthalene rectifying tower and emptying a safety valve comprises an industrial naphthalene rectifying tower 1, an industrial naphthalene/raw material heat exchanger 2, an industrial naphthalene vaporization water-cooling condensation cooler 3, an industrial naphthalene vaporization air-cooling condensation cooler 4, an industrial naphthalene reflux tank 5, an industrial naphthalene reflux pump 6, a safety valve 7, a first valve 8, a second valve 9 and a throttle orifice plate 10.

An outlet pipeline at the top of the industrial naphthalene rectifying tower 1 is divided into two branches after passing through the industrial naphthalene/raw material heat exchanger 2, one branch is connected with an inlet pipeline of the industrial naphthalene vaporization water-cooling condensation cooler 3, and the other branch is connected with an inlet pipeline of the industrial naphthalene vaporization air-cooling condensation cooler 4 through a throttling orifice plate 10.

The discharge pipeline of the safety valve 7 at the top of the industrial naphthalene rectifying tower 1 is connected with the inlet pipeline of the industrial naphthalene vaporization air-cooling condensation cooler 4.

An outlet pipeline of the industrial naphthalene vaporization water-cooling condensation cooler 3 is joined with an outlet pipeline of the industrial naphthalene vaporization air-cooling condensation cooler 4 and then is connected with an inlet pipeline at the top of the industrial naphthalene reflux tank 5.

An outlet pipeline at the bottom of the industrial naphthalene reflux tank 5 is connected with an inlet at the upper part of the industrial naphthalene rectifying tower 1, and an industrial naphthalene reflux pump 6 is arranged on the outlet pipeline at the bottom of the industrial naphthalene reflux tank 5. An outlet pipeline at the upper part of the industrial naphthalene reflux tank 5 is connected with the industrial naphthalene high-level tank.

The first valve 8 is installed on the outlet pipeline of the industrial naphthalene rectification tower 1. One end of the second valve 9 is connected with an outlet pipeline of the industrial naphthalene rectifying tower 1 through a pipeline, and the other end is connected with an inlet pipeline of the industrial naphthalene vaporization air-cooling condensation cooler 4 through a pipeline.

A process for extracting and emptying a safety valve at the top of an industrial naphthalene rectifying tower comprises the following steps:

1) cooling of industrial naphthalene vapor: the industrial naphthalene vaporization water-cooling condensation cooler 3 and the industrial naphthalene vaporization air-cooling condensation cooler 4 are connected in parallel for operation, most industrial naphthalene vapor adopts the industrial naphthalene vaporization water-cooling condensation cooler 3, and a small part adopts the industrial naphthalene vaporization air-cooling condensation cooler 4, so that the water temperature of the industrial naphthalene in the industrial naphthalene condensation cooler at the lower part of the industrial naphthalene vaporization air-cooling condensation cooler 4 is kept at 80-100 ℃, and the industrial naphthalene vaporization water-cooling condensation cooler is convenient to use when a safety valve is used for emergency emptying.

2) The industrial naphthalene vaporization air-cooling condensation cooler 4 is required to ensure the total discharge amount of cooling when the safety valve is in emergency emptying.

3 the industrial naphthalene vapor amount cooled by the industrial naphthalene vaporization air-cooling condensation cooler 4 is controlled by the throttle orifice 10, when a cold season comes, the first valve 8 is opened to be large, the second valve 9 is opened to be small, the treatment capacity of equipment can be improved, and the industrial naphthalene vaporization air-cooling condensation cooler 4 can be wholly or partially adopted for cooling, so that the energy is saved and the safety is realized.

4) The discharge pipeline of the safety valve 7 at the top of the industrial naphthalene rectifying tower is connected with the inlet pipeline of the industrial naphthalene steam of the industrial naphthalene vaporization air-cooling condensation cooler 4, and the industrial naphthalene vaporization air-cooling condensation cooler 4 can play a cooling role when the cooling water or reflux is interrupted or the reboiler inputs too much heat to cause the overpressure of the industrial naphthalene rectifying tower 1.

5) Under the normal operation condition, industrial naphthalene vapor at the top of an industrial naphthalene distillation tower 1 exchanges heat with raw materials through an industrial naphthalene/raw material heat exchanger 2, and is cooled in two ways, one way is cooled through an industrial naphthalene vaporization water-cooling condensation cooler 3, the other way is limited by a throttling orifice plate 10 and is cooled through an industrial naphthalene vaporization air-cooling condensation cooler 4, two ways of liquid industrial naphthalene after condensation and cooling automatically flow into an industrial naphthalene reflux tank 5, one part of liquid industrial naphthalene is sent back to the top of the industrial naphthalene distillation tower 1 through an industrial naphthalene reflux pump 6 to be refluxed for controlling the temperature at the top of the distillation tower, and the rest of liquid industrial naphthalene is sent to an industrial naphthalene overhead tank.

6) When the top of the industrial naphthalene rectifying tower 1 is over-pressure, the safety valve 7 jumps and is emptied, the industrial naphthalene vapor basically and completely enters the industrial naphthalene vaporization air-cooling condensation cooler 4 for cooling, the liquid industrial naphthalene after condensation and cooling is discharged into the industrial naphthalene reflux tank 5, a small part of the industrial naphthalene vapor enters the industrial naphthalene vaporization water-cooling condensation cooler 3 through the throttling orifice plate 10, and even if no circulating cooling water exists, the small part of the industrial naphthalene vaporization water-cooling condensation cooler 3 can meet the cooling requirement through natural heat dissipation.

The industrial naphthalene vaporization air-cooling condensation cooler is introduced as an alternative cooler for the industrial naphthalene vapor, and the industrial naphthalene vaporization air-cooling condensation cooler is selected to replace an air condensation cooler or a circulating water cooler, so that the industrial naphthalene vapor is prevented from generating crystallization to block a pipeline during cooling, and the industrial naphthalene vaporization air-cooling condensation cooler is energy-saving and safe.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.