CN115779633A - Adsorption tower shutdown cooling system and method - Google Patents

Abstract

The invention belongs to the field of chemical industry, and specifically relates to an adsorption tower cooling system and method, including a desorbent cooling pipeline, the desorbent cooling pipeline is connected with a heat exchanger group, and the desorbent cooling pipeline passes behind the heat exchanger group The crossing pipeline is connected to the raffinate inlet of the raffinate tower, and the gas phase outlet at the top of the raffinate tower is connected to the air cooler at the top of the tower, the reflux tank, the reflux pump and the raffinate tower in sequence through the pipeline, and the outlet of the raffinate tower The outlet at the bottom of the tower is connected to the feed pipeline of the adsorption tower through a pipeline, the desorbent cooling pipeline is connected to the feed pipeline of the adsorption tower, and the reflux tank is provided with a water bag dewatering mechanism. In the present invention, the cooling process of the desorbent is transformed into the raffinate tower, the circulation is established in advance, and the desorbent is used before the cooling of the adsorption tower, and the water bag is dehydrated through the return tank of the raffinate tower to prevent water from being brought into the adsorption tower.

Description

Adsorption tower shutdown cooling system and method

technical field

The invention belongs to the field of chemical industry, and in particular relates to a system and method for stopping and cooling an adsorption tower.

Background technique

After the adsorption tower stops, it needs to cool down to ensure that the adsorption tower is in a safe state, and prevent the material in the tower from vaporizing and damaging the adsorbent due to the low pressure of the adsorption tower. Therefore, the adsorption tower is cooled through the desorbent cooling process and the cooling rate is controlled. However, the returned material from the underground waste oil tank also passes through the desorbent cooling process. The returned material contains water, and the low point of the process accumulates water for a long time. Using this process will bring some of the stored water into the adsorption tower and damage the performance of the adsorbent.

Contents of the invention

According to the defects in the above-mentioned prior art, the object of the present invention is to provide a system and method for stopping the cooling of the adsorption tower, which can remove the water stored in the cooling process of the desorbent in advance, meet the cooling requirements of the adsorption tower, and protect the adsorbent at the same time.

In order to achieve the above object, the technical solution adopted in the present invention is: the adsorption tower parking cooling system, including the desorbent cooling pipeline, the desorbent cooling pipeline is connected with a heat exchanger group, and the desorbent cooling pipeline is behind the heat exchanger group The road is connected to the raffinate feed inlet of the raffinate tower through a spanning pipeline, and the gas phase outlet at the top of the raffinate tower is connected to the top air cooler, reflux tank, reflux pump and raffinate tower in sequence through pipelines, and the raffinate The outlet at the bottom of the tower is connected to the feed pipeline of the adsorption tower through a pipeline, the desorbent cooling pipeline is connected to the feed pipeline of the adsorption tower, and the reflux tank is provided with a water bag water removal mechanism.

Further, double gate valves and 8-shaped blind plates are arranged on the crossing pipeline.

Further, a feed valve is provided on the feed pipeline of the adsorption tower, the inlet of the desorbent cooling pipeline is connected to the front of the feed valve, the outlet of the desorbent cooling pipeline is connected to the rear of the feed valve, and the desorbent cooling pipeline is connected to the rear of the feed valve. The feed pipeline of the adsorption tower forms a loop; the feed pipeline of the adsorption tower is provided with a finished product bottom reboiler, and the finished product bottom reboiler is arranged on the front road of the inlet of the desorbent cooling pipeline.

Further, the inlet and outlet of the desorbent cooling pipeline are both provided with double valves, and the desorbent cooling pipeline is connected to the storage tank through the oil return line, and the oil return line is connected to the front of the outlet double valve.

Further, the heat exchanger group includes a desorbent air cooler and a desorbent water cooler, and the desorbent cooling pipeline is sequentially connected to the desorbent air cooler and the desorbent water cooler, and the desorbent water cooler is provided with a water-cooled jumper in parallel, and the water-cooled The two ends of the jumper are connected to the front and rear of the desorbent water cooler.

Further, the raffinate tower is provided with a heat exchanger at the bottom of the raffinate tower feed tower, which is connected to the inlet of the heat exchanger at the bottom of the raffinate tower feed tower through a pipeline, and is fed to the bottom of the raffinate tower through the raffinate tower. After heat exchange, the heat exchanger is connected to the raffinate feed port of the raffinate tower; the bottom outlet of the raffinate tower is connected to the raffinate tower bottom pump and the raffinate tower feed tower bottom through a pipeline for heat exchange The device is connected to the feed pipeline of the adsorption tower through a pipeline after heat exchange at the bottom heat exchanger of the raffinate tower; the raffinate tower is connected to the isomerization reaction system through a side-drawing line.

Further, the adsorption tower shutdown cooling system also includes an underground tank for recovering the materials that are airtightly discharged in the adsorption tower system. The outlet of the underground tank is provided with an underground tank outlet pump. The underground tank outlet pump is connected to the raffinate tower and the desorbent regeneration tower respectively. And desorbent cooling pipeline.

Further, the outlet pump of the underground tank is provided with a tank return line for adjusting the outlet pressure and flow rate of the pump, the tank return line returns to the underground tank, and the tank return line is provided with a sight glass at the outlet of the outlet pump of the underground tank.

Further, the outlet pump of the underground tank is provided with an outlet flowmeter.

Further, the water bag dewatering mechanism is provided with a drainage line.

The method of stopping and cooling the adsorption tower, the raffinate and the desorbent at the bottom of the liquid tower are combined, after being cooled by the reboiler at the bottom of the finished product tower, it is then cooled by the desorbent air cooler and the desorbent water cooler in turn, and the cooled desorbent is sent across the pipeline Feed to the raffinate tower and send it to the raffinate tower after heat exchange at the bottom of the tower heat exchanger. The water stored in the pipeline when the desorbent passes through the desorbent water cooler enters and exits the pipeline along with the C8 aromatics to the gas phase outlet at the top of the raffinate tower, and passes through the top of the tower The air cooler is cooled to the reflux tank, and the water bag in the reflux tank removes the stored water, and then the adsorption tower is cooled through the desorbent cooling process.

Further, the temperature of the desorbent entering the adsorption tower is not lower than the current temperature of the adsorption tower by 25°C.

The beneficial effects of the present invention are: the present invention transforms the cooling process of the desorbent to the raffinate tower, establishes circulation in advance, and uses it before cooling the adsorption tower, and dehydrates the water bag through the return tank of the raffinate tower to prevent water from being brought into the adsorption tower.

Description of drawings

Fig. 1 is the process flow diagram of the adsorption tower parking cooling system of the present invention;

In the figure: 1. Desorbent cooling pipeline, 2. Crossover pipeline, 3. Raffinate tower, a. Raffinate feed inlet, b. Tower top gas phase outlet, c. C8 aromatics reflux port, d. Desorbent tower Bottom outlet, e, side mining line, 4, tower top air cooler, 5, reflux tank, 6, reflux pump, 7, adsorption tower feed pipeline, 8, water bag water removal mechanism, 9, double gate valve, 10, 8 Word blind plate, 11. Feed valve, 12. Finished product bottom reboiler, 13. Oil return pipeline, 14. Desorbent air cooler, 15. Desorbent water cooler, 16. Water cooling cross-line, 17. Raffinate Tower feed tower bottom heat exchanger, 18. Raffinate tower bottom pump, 19. Underground tank, 20. Underground tank outlet pump, 21. Tank return line, 22. Sight glass, 23. Outlet flowmeter;

A. Extract liquid tower bottom, B. Adsorption tower, C. Storage tank, D. Isomerization reaction system, E. Raffinate tower feed mixing tank, F. Desorbent regeneration tower.

Detailed ways

In order to make the structure and function of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention.

Referring to accompanying drawing 1, the adsorption tower shutdown cooling system includes a desorbent cooling pipeline 1, the desorbent cooling pipeline 1 is connected with a heat exchanger group, and the desorbent cooling pipeline 1 is connected by a spanning pipeline 2 at the rear of the heat exchanger group To the raffinate feed port a of the raffinate tower 3, the gaseous phase outlet b at the top of the raffinate tower is connected to the top air cooler 4, the reflux tank 5, the reflux pump 6 and the reflux of the raffinate tower 3 in sequence through pipelines port c, the outlet d at the bottom of the raffinate tower is connected to the adsorption tower feed line 7 through a pipeline, the desorbent cooling line 1 is connected to the adsorption tower feed line 7, and the reflux tank 5 is provided with a water bag removal A water mechanism 8, the water bag dewatering mechanism 8 is provided with a drainage line.

Further, the crossover pipeline 2 is provided with a double gate valve 9 and a figure 8 blind plate 10 .

Further, the adsorption tower feed line 7 is provided with a feed valve 11, the inlet of the desorbent cooling pipeline is connected to the front path of the feed valve 11, and the outlet of the desorbent cooling pipeline is connected to the back path of the feed valve 11. The agent cooling pipeline 1 forms a loop with the adsorption tower feed pipeline 7; the finished product tower bottom reboiler 12 is arranged on the adsorption tower feed pipeline 7, and the finished product tower bottom reboiler 12 is arranged on the front road of the desorbent cooling pipeline inlet .

Further, the inlet and outlet of the desorbent cooling pipeline 1 are equipped with double valves, the desorbent cooling pipeline 1 is connected to the storage tank C through the oil return line 13, and the oil return line 13 is connected to the front of the outlet double valve .

Further, the heat exchanger group includes a desorbent air cooler 14 and a desorbent water cooler 15, and the desorbent cooling line 1 is sequentially connected to the desorbent air cooler 14 and the desorbent water cooler 15, and the desorbent water cooler 15 is arranged in parallel There is a water-cooling jumper 16, and the two ends of the water-cooling jumper 16 are connected to the front path and the rear path of the desorbent water cooler 15.

Further, the raffinate tower 3 is provided with a heat exchanger 17 at the bottom of the raffinate tower feeding tower, which is connected across the pipeline 2 to the inlet of the heat exchanger 17 at the bottom of the raffinate tower feeding tower, and passes through the raffinate tower The feed tower bottom heat exchanger 17 is connected to the raffinate feed port a of the raffinate tower 3 after heat exchange; the tower bottom outlet d of the raffinate tower 3 is connected to the raffinate tower bottom pump 18 and the raffinate tower bottom pump 18 through a pipeline. The raffinate tower feed tower bottom heat exchanger 17 is connected to the adsorption tower feed pipeline 7 through a pipeline after the raffinate tower feed tower bottom heat exchanger 17 is heat-exchanged; Line e connects to isomerization reaction system D.

Based on the above technical scheme, it should be noted that the raffinate tower 3 is fed through the raffinate tower feeding mixing tank E, and the raffinate tower feeding mixing tank E is connected to the bottom heat exchanger of the raffinate tower feeding tower On the 17 inlet, the raffinate tower feed mixing tank E is used to reduce the impact of feed composition changes on the operation of the raffinate tower. The raffinate tower feed tower bottom heat exchanger 17 performs heat exchange between the raffinate tower feed and tower bottom discharge.

Further, the adsorption tower parking cooling system also includes an underground tank 19 for recovering the material that is airtightly discharged in the adsorption tower system. The outlet of the underground tank 19 is provided with an underground tank outlet pump 20, and the underground tank outlet pump 10 is connected to the raffinate tower 3 respectively. , Desorbent regeneration tower F and desorbent cooling line 1.

Further, the underground tank outlet pump 20 is provided with a return tank line 21 for adjusting the pump outlet pressure and flow rate, and the return tank line 21 returns to the underground tank 19, and the outlet of the underground tank outlet pump 20 is set on the return tank line 21. Mirror 22. The underground tank outlet pump 20 is provided with an outlet flow meter 23 .

Based on the above technical solution, it should be noted that the underground tank 19 mainly contains C8 aromatics and desorbent. The underground tank 19 is mainly used to recover the related airtight discharge materials in the adsorption tower system, and send them to the raffinate tower 3 or the desorbent regeneration tower F through the pump outlet, or return the oil to the storage through the process of the desorbent air cooler 14→desorbent water cooler 15 Tank C, the pump outlet has a tank return line 21 with a sight glass 22 to adjust the pump outlet pressure and flow. The inlet pipeline of the underground tank is mainly a close-packed pipeline in the adsorption tower system, which merges to form an underground close-packed pipe network to the underground tank to recover and discharge materials. The desorbent regeneration tower F is used to remove heavy materials accumulated in the desorbent for a long time.

The method of stopping and cooling the adsorption tower, the raffinate and the desorbent at the bottom of the extracted liquid are combined, and after being cooled by the reboiler 12 at the bottom of the finished product tower, they are cooled by the desorbent air cooler 14 and the desorbent water cooler 15 in turn, and the cooled desorbent passes through Sent across the pipeline 2 to the raffinate tower feed tower bottom heat exchanger 17 and then sent to the raffinate tower 3, the desorbent passes through the desorbent water cooler 14 and the water stored in the pipeline along with the C8 aromatics to the raffinate tower The top gas phase outlet is cooled to the reflux tank 5 through the tower top air cooler 4, and the water bag in the reflux tank removes the stored water, and then the adsorption tower is cooled through the desorbent cooling process.

Further, the temperature of the desorbent entering the adsorption tower is not lower than the current temperature of the adsorption tower by 25°C.

Based on the above technical solution, it should be noted that each pipeline and reactor are controlled on and off by valves, as shown in Fig. 1 , and thus will not be described one by one.

The present invention solves the problem of long-term accumulation of water at the low point of the desorbent cooling process, which will bring part of the stored water into the adsorption tower to damage the performance of the adsorbent when the adsorption tower is stopped, and transforms the desorbent cooling process to the raffinate Tower, establish a cycle in advance, and dehydrate the water bag through the raffinate tower reflux tank, and use it before cooling the adsorption tower to avoid water being brought into the adsorption tower. Ensure the cooling of the adsorption tower and protect the adsorbent.

The specific working principle is as follows:

Normal process: Raffinate tower feeds mixing tank E material (C8 aromatics + desorbent) to raffinate tower feed tower bottom heat exchanger 17 after heating, then enters raffinate tower 3, raffinate tower top gas phase (C8 Aromatic hydrocarbons) are cooled to the liquid phase by the air cooler 4 at the top of the tower to the reflux tank 5, and the material in the reflux tank 5 is sent to the raffinate tower 3 as reflux through the reflux pump 6, and the water stored in the reflux tank 5 is removed through the water bag, and the raffinate The side line of the tower (C8 aromatics) is sent to the isomerization reaction system as liquid feed, and the raffinate tower bottom material (desorbent) passes through the raffinate tower bottom pump 18 to the raffinate tower feed tower bottom heat exchanger 17 After cooling down, it merges with the bottom material (desorbent) from the extract liquid, passes through the product bottom reboiler 12 and cools down to the adsorption tower B for adsorption separation.

The material in the underground tank 19 is sent to the raffinate tower 3 or the desorbent regeneration tower F through the outlet of the underground tank outlet pump 20, or the oil is returned to the storage tank C through the process of the desorbent air cooler 14→desorbent water cooler 15, according to the material of the underground tank 19 Sampling and analysis results selection process, the minimum return line at the outlet of the underground tank outlet pump 20 returns to the underground tank to adjust the pump outlet pressure and flow.

Desorbent cooling process: the raffinate and the extracted liquid desorbent at the bottom of the tower are combined, cooled by the reboiler 12 at the bottom of the finished product tower, cooled by the desorbent air cooler 14, then cooled by the desorbent water cooler 15, and finally to the adsorption tower. Overall cooling, the temperature of the desorbent entering the adsorption tower should not be lower than the current temperature of the adsorption tower by 25°C, to avoid damage to the internal parts of the adsorption tower, that is, the temperature of the adsorption tower - the temperature of the desorbent ≤ 25°C, which can be cooled by desorbent air cooler 14 and desorbent water Device 15 is adjusted. The disadvantage of this process is that the low point of the inlet and outlet pipeline of the desorbent water cooler may store water, and directly entering the adsorption tower will damage the adsorbent in the adsorption tower.

The process after transformation: the raffinate and the extracted liquid desorbent at the bottom of the tower are combined, cooled by the reboiler 12 at the bottom of the finished product tower, cooled by the desorbent air cooler 14, and then cooled by the desorbent water cooler 15, and then transferred to the underground tank through the transformation. Oil line, to raffinate tower feed tower bottom heat exchanger 17, to raffinate tower 3, desorbent water cooler inlet and outlet pipeline storage water will follow C8 aromatics to raffinate tower top gas phase, and pass through tower top air cooler 4 Cool to the reflux tank 5, and the water bag in the reflux tank 5 removes the stored water. After the water is removed, the desorbent cooling process is used to cool the adsorption tower to achieve the purpose of protecting the adsorbent from being damaged by water.

The above enumerated are only the preferred embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments, and many variations are possible. All deformations that can be directly derived or associated by those skilled in the art from the content disclosed in the present invention should be considered as the protection scope of the present invention.

Claims (10)

1. Adsorption tower system of cooling that parks, its characterized in that: the tower bottom outlet of the raffinate tower is connected to an adsorption tower feeding pipeline through a pipeline, the desorbent cooling pipeline is connected to an adsorption tower feeding pipeline through a water drum water removing mechanism, and the desorbent cooling pipeline is connected to a heat exchanger set.

2. The adsorption tower shutdown cooling system of claim 1, wherein: and a double gate valve and an 8-shaped blind plate are arranged on the crossing pipeline.

3. The adsorption tower shutdown cooling system of claim 1, wherein: a feed pipe of the adsorption tower is provided with a feed valve, the inlet of a desorbent cooling pipeline is connected with the front path of the feed valve, the outlet of the desorbent cooling pipeline is connected with the rear path of the feed valve, and the desorbent cooling pipeline and the feed pipe of the adsorption tower form a loop; and a finished product tower bottom reboiler is arranged on the feeding pipe line of the adsorption tower, and the finished product tower bottom reboiler is arranged on the front path of the inlet of the desorbent cooling pipeline.

4. The adsorption tower shutdown cooling system of claim 1, wherein: the inlet and the outlet of the desorbent cooling pipeline are both provided with double valves, the desorbent cooling pipeline is connected with the storage tank through an oil outlet pipeline, and the oil outlet pipeline is connected to the front path of the outlet double valve.

5. The adsorption tower shutdown cooling system of claim 1, wherein: the heat exchanger group comprises a desorbent air cooler and a desorbent water cooler, wherein the desorbent cooling pipeline is sequentially connected with the desorbent air cooler and the desorbent water cooler, the desorbent water cooler is provided with a water cooling span line in parallel, and two ends of the water cooling span line are connected with a front path and a back path of the desorbent water cooler.

6. The adsorption tower shutdown cooling system of claim 1, wherein: the raffinate tower is provided with a raffinate tower feeding tower bottom heat exchanger, a crossover pipeline is connected to an inlet of the raffinate tower feeding tower bottom heat exchanger, and the heat exchange of the raffinate tower feeding tower bottom heat exchanger is connected with a raffinate feeding hole of the raffinate tower; the tower bottom outlet of the raffinate tower is connected with a raffinate tower bottom pump and a raffinate tower feeding tower bottom heat exchanger through pipelines, and is connected to an adsorption tower feeding pipeline through a pipeline after heat exchange is carried out by the raffinate tower feeding tower bottom heat exchanger; the raffinate column is connected to the isomerization reaction system via a side-draw line.

7. The adsorption tower shutdown cooling system of claim 1, wherein: the device also comprises an underground tank for recovering the materials which are hermetically discharged in the adsorption tower system, wherein an outlet of the underground tank is provided with an underground tank outlet pump, and the underground tank outlet pump is respectively connected with the raffinate tower, the desorbent regeneration tower and the desorbent cooling pipeline.

8. The adsorption tower shutdown cooling system of claim 7, wherein: the underground tank outlet pump is provided with a tank returning line for adjusting the pressure and the flow of the outlet of the pump, the tank returning line returns to the underground tank, and a viewing mirror is arranged at the outlet of the underground tank outlet pump on the tank returning line; the underground tank outlet pump is provided with an outlet flowmeter.

9. The method for stopping the adsorption tower and reducing the temperature is characterized in that: the raffinate converges with a desorbent at the bottom of the extract tower, the desorbent is cooled by a reboiler at the bottom of a finished product tower and then sequentially cooled by a desorbent air cooler and a desorbent water cooler, the cooled desorbent is sent to a raffinate tower feeding tower bottom heat exchanger through a crossover pipeline for heat exchange and then sent to a raffinate tower, the water stored when the desorbent passes through a desorbent water cooler inlet and outlet pipeline is sent to a raffinate tower top gas phase outlet along with C8 aromatic hydrocarbon, the residual water is cooled to a reflux tank through a tower top air cooler, the water stored in the reflux tank is removed by a water drum, and the temperature of the adsorption tower is cooled through a desorbent cooling process.

10. The method for stopping and cooling the adsorption tower according to claim 9, characterized in that: the temperature of the desorbent entering the adsorption tower is not lower than the current temperature of the adsorption tower by 25 ℃.

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