阅读说明：本技术 一种用于采三混馏分减压焦油蒸馏塔的真空系统及工艺 (Vacuum system and process for distillation tower for collecting three-mixed fraction vacuum tar ) 是由 张树福 于 2020-12-30 设计创作，主要内容包括：本发明涉及冶金焦化技术领域,尤其涉及一种用于采三混馏分减压焦油蒸馏塔的真空系统及工艺。包括回流槽、真空捕集器与真空冷却器；回流槽用隔板隔成两个独立的一室与二室,二室与真空捕集器直连,一室、二室通过管道与真空冷却器连接,真空捕集器通过管道与真空冷却器、放散系统相连；减压焦油蒸馏塔塔顶通过管道与一室相连,一室、二室均通过管道与回流泵相连,回流泵通过管道与减压焦油蒸馏塔塔顶相连。降低真空气中的与洗油相似的凝缩油气含量,保证真空循环液洗油的质量,增加运行时间,减少更换周期；降低进入液环式真空泵的真空气温度,保证液环式真空泵正常的抽气能力,不至于因进入的真空气温度过高,而降低了真空泵抽气能力。(The invention relates to the technical field of metallurgical coking, in particular to a vacuum system and a process for a distillation tower for extracting three-mixed fraction vacuum tar. Comprises a reflux tank, a vacuum catcher and a vacuum cooler; the reflux tank is divided into two independent first and second chambers by a partition board, the first and second chambers are directly connected with a vacuum catcher, the first and second chambers are connected with a vacuum cooler through pipelines, and the vacuum catcher is connected with the vacuum cooler and a diffusing system through pipelines; the tower top of the reduced pressure tar distillation tower is connected with the first chamber through a pipeline, the first chamber and the second chamber are both connected with a reflux pump through pipelines, and the reflux pump is connected with the tower top of the reduced pressure tar distillation tower through a pipeline. The condensed oil gas content similar to the washing oil in the vacuum air is reduced, the quality of the washing oil of the vacuum circulating liquid is ensured, the running time is increased, and the replacement period is shortened; the temperature of the vacuum air entering the liquid ring vacuum pump is reduced, the normal air pumping capacity of the liquid ring vacuum pump is ensured, and the air pumping capacity of the vacuum pump is not reduced due to overhigh temperature of the entering vacuum air.)

1. A vacuum system for adopting a three-mixed fraction decompression tar distillation tower is characterized by comprising a reflux tank, a vacuum catcher and a vacuum cooler; the reflux tank is divided into two independent first and second chambers by a partition plate, the first and second chambers are directly connected with a vacuum trap, the first and second chambers are connected with a vacuum cooler through pipelines, and the vacuum trap is connected with the vacuum cooler and a diffusion system through pipelines; the tower top of the reduced pressure tar distillation tower is connected with the first chamber through a pipeline, the first chamber and the second chamber are both connected with a reflux pump through pipelines, and the reflux pump is connected with the tower top of the reduced pressure tar distillation tower through a pipeline.

2. The vacuum system for the vacuum distillation tower for the recovery of the three-mixed fraction vacuum tar as claimed in claim 1, wherein: a mist catcher is arranged on a pipeline connecting the first chamber and the vacuum cooler.

3. The vacuum system for the vacuum distillation tower for the recovery of the three-mixed fraction vacuum tar as claimed in claim 1, wherein: and a regulating valve, a self-operated regulating valve, a liquid ring vacuum pump, a vacuum liquid cooler and a gas-liquid separation tank are arranged on a pipeline connecting the vacuum catcher and the diffusing system, and the liquid ring vacuum pump is connected with the gas-liquid separation tank through a pipeline.

4. The vacuum system for the vacuum distillation tower for the recovery of the three-mixed fraction vacuum tar as claimed in claim 1, wherein: and a heat exchanger and a three-mixed fraction cooler are arranged on a pipeline connected with the first chamber at the top of the reduced pressure tar distillation tower.

5. A process for the continuous distillation of tar under reduced pressure from three mixed fractions based on the vacuum system for the distillation tower of tar under reduced pressure from three mixed fractions as claimed in claim 1, 2, 3 or 4, which comprises the following steps:

1) the three-mixed oil gas from the top of the reduced pressure tar distillation tower is condensed and cooled in a heat exchanger, then enters a three-mixed fraction cooler for cooling, and the three-mixed oil cooled to 80-100 ℃ enters one chamber of a double-chamber reflux tank; pumping out the three mixed oils by a reflux pump, returning one part of the three mixed oils to the top of the vacuum tar distillation tower, and sending the other part of the three mixed oils to the outside;

2) vacuum gas at the top of the first chamber of the double-chamber reflux tank sequentially passes through the mist catcher, the vacuum cooler and the vacuum catcher and finally enters the liquid ring vacuum pump, gas-liquid mixed liquid is sent into the gas-liquid separation tank by the liquid ring vacuum pump, gas-liquid separation is carried out at the gas-liquid separation tank, and the gas enters the diffusing system for unified treatment;

3) washing oil is selected as circulating liquid of a liquid ring vacuum pump for distilling the reduced pressure tar, enters a vacuum liquid cooler from a gas-liquid separation tank, is cooled, and then returns to the liquid ring vacuum pump for recycling;

4) the negative pressure at the top of the reduced pressure tar distillation tower is regulated by a gas exchange pipe regulating valve at the inlet and the outlet of a liquid ring vacuum pump, and if the vacuum is not condensed and the gas amount is not enough, nitrogen gas is supplemented by a self-operated regulating valve.

6. The vacuum continuous distillation process for extracting the three-mixed fraction tar according to claim 5, wherein the mist trap in the step 2) traps oil mist carried in high-temperature vacuum air, then the oil mist enters a vacuum cooler for further cooling, the oil mist which is not trapped is changed into oil drops, the oil drops automatically flow to the two chambers of the reflux tank, and the gas enters the vacuum trap.

7. The vacuum continuous distillation process for extracting the three-mixed fraction tar according to claim 5, wherein the gas from the upper part of the vacuum cooler in the step 2) enters a vacuum trap, the vacuum gas is finally and completely separated from the condensed oil mist, the gas is subjected to cyclone separation and then enters a liquid ring vacuum pump from the middle top of the vacuum trap, and oil drops automatically flow to the second chamber of the reflux tank along the side wall of the vacuum trap.

Technical Field

The invention relates to the technical field of metallurgical coking, in particular to a vacuum system and a process for a distillation tower for extracting three-mixed fraction vacuum tar.

Background

Distillation of tar during coal tar processing is the most basic conventional method for splitting tar under industrial conditions. At present, the domestic tar distillation process is divided into a normal pressure distillation process, an atmospheric-vacuum distillation process and a vacuum distillation process according to pressure; the process is divided into a narrow fraction process and a three-mixed fraction process according to cut fractions, and the narrow fraction process and the three-mixed fraction process are combined to combine different process flows.

Under the premise of determining a narrow-cut or three-mixed-cut product scheme, a tar normal-vacuum continuous distillation process and a tar vacuum continuous distillation process are development trends of tar processing at present and should be preferred. The purpose of the pressure reduction is to reduce the distillation temperature, accelerate the distillation speed and prevent the heating system from coking. And the quality of cut fraction can be improved, and the extraction rate of naphthalene can be improved.

At present, three-mixed oil gas coming out from the top of a reduced pressure tar distillation tower in a three-mixed fraction tar reduced pressure continuous distillation process exchanges heat with raw material tar, then automatically flows to a reflux tank through a three-mixed fraction cooler, the gas at the top of the reflux tank is directly pumped by a liquid ring vacuum pump, gas-liquid mixed liquid at the outlet of the liquid ring vacuum pump is sent to a gas-liquid separation tank, the liquid returns to the vacuum pump through the vacuum liquid cooler and is recycled, the gas is discharged into a diffusing system from the top of the gas-liquid separation tank for treatment, and the negative pressure at the top of the reduced pressure tar distillation tower is adjusted through a vacuum pump traffic.

In the process of adopting the three-mixed fraction tar and carrying out the reduced pressure continuous distillation, a vacuum system is a very important part in the whole process device, and plays a vital role in the whole tar distillation device and the product quality if the vacuum system can be normally, continuously, stably and safely operated. From the problems of feedback from the site, vacuum systems always have more or less such problems, the main ones being as follows:

1) the vacuum contains condensed oil gas with different components, the properties of the oil gas are similar to those of washing oil, and according to the similar compatibility principle, the oil gas similar to the washing oil in the vacuum is absorbed by the washing oil of the vacuum circulating liquid, so that the washing oil quality of the vacuum circulating liquid is reduced quickly, the washing oil of the vacuum circulating liquid needs to be replaced frequently and periodically, and the continuous and stable operation of tar production is seriously influenced.

2) The working temperature of the reflux tank is 80-100 ℃, meanwhile, in order to prevent naphthalene from being separated out in vacuum gas, the accompanying design of a vacuum gas pipeline is adopted, the temperature of the vacuum gas is basically 80-100 ℃, the high temperature is directly introduced into a liquid ring vacuum pump, the temperature of vacuum circulation liquid washing oil is increased, the air extraction capacity of the vacuum pump is insufficient, and the quality of the three-mixed fraction is reduced and even unqualified.

In conclusion, in the process of adopting the three-mixed fraction tar and carrying out the vacuum continuous distillation, the two problems need to be solved urgently so as to ensure the continuous, stable and safe operation of a tar device.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides a vacuum system and a process for adopting a three-mixed fraction reduced pressure tar distillation tower, which firstly reduce the content of condensed oil gas similar to washing oil in vacuum air, ensure the quality of the washing oil of vacuum circulating liquid, increase the running time and reduce the replacement period; and secondly, the temperature of the vacuum air entering the liquid ring vacuum pump is reduced, the normal air exhaust capacity of the liquid ring vacuum pump is ensured, and the air exhaust capacity of the vacuum pump is not reduced due to overhigh temperature of the entering vacuum air.

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

a vacuum system for adopting three-mixed fraction decompression tar distillation tower comprises a reflux tank, a vacuum catcher and a vacuum cooler; the reflux tank is divided into two independent first and second chambers by a partition plate, the first and second chambers are directly connected with a vacuum trap, the first and second chambers are connected with a vacuum cooler through pipelines, and the vacuum trap is connected with the vacuum cooler and a diffusion system through pipelines; the tower top of the reduced pressure tar distillation tower is connected with the first chamber through a pipeline, the first chamber and the second chamber are both connected with a reflux pump through pipelines, and the reflux pump is connected with the tower top of the reduced pressure tar distillation tower through a pipeline.

A mist catcher is arranged on a pipeline connecting the first chamber and the vacuum cooler.

And a regulating valve, a self-operated regulating valve, a liquid ring vacuum pump, a vacuum liquid cooler and a gas-liquid separation tank are arranged on a pipeline connecting the vacuum catcher and the diffusing system, and the liquid ring vacuum pump is connected with the gas-liquid separation tank through a pipeline.

And a heat exchanger and a three-mixed fraction cooler are arranged on a pipeline connected with the first chamber at the top of the reduced pressure tar distillation tower.

A vacuum continuous distillation process for collecting three-mixed fraction tar comprises the following steps:

1) the three-mixed oil gas from the top of the reduced pressure tar distillation tower is condensed and cooled in a heat exchanger, then enters a three-mixed fraction cooler for cooling, and the three-mixed oil cooled to 80-100 ℃ enters one chamber of a double-chamber reflux tank; pumping out the three mixed oils by a reflux pump, returning one part of the three mixed oils to the top of the vacuum tar distillation tower, and sending the other part of the three mixed oils to the outside;

2) vacuum gas at the top of the first chamber of the double-chamber reflux tank sequentially passes through the mist catcher, the vacuum cooler and the vacuum catcher and finally enters the liquid ring vacuum pump, gas-liquid mixed liquid is sent into the gas-liquid separation tank by the liquid ring vacuum pump, gas-liquid separation is carried out at the gas-liquid separation tank, and the gas enters the diffusing system for unified treatment;

the mist catcher catches oil mist carried in high-temperature vacuum air, then the oil mist enters the vacuum cooler for further cooling, the oil mist which is not caught is changed into oil drops, the oil drops automatically flow to the second chamber of the backflow groove, and the gas enters the vacuum catcher;

gas from the upper part of the vacuum cooler enters a vacuum trap, the vacuum gas is finally and thoroughly separated from condensed oil mist, the gas is subjected to cyclone separation and then enters a liquid ring vacuum pump from the top of the middle of the vacuum trap, and oil drops automatically flow to a second chamber of the backflow groove along the side wall of the vacuum trap;

3) washing oil is selected as circulating liquid of a liquid ring vacuum pump for distilling the reduced pressure tar, enters a vacuum liquid cooler from a gas-liquid separation tank, is cooled, and then returns to the liquid ring vacuum pump for recycling;

4) the negative pressure at the top of the reduced pressure tar distillation tower is regulated by a gas exchange pipe regulating valve at the inlet and the outlet of a liquid ring vacuum pump, and if the vacuum is not condensed and the gas amount is not enough, nitrogen gas is supplemented by a self-operated regulating valve.

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

1) the condensed oil gas in the vacuum is separated by the mist catcher, the vacuum cooler and the vacuum cyclone catcher for three times, the content of condensed gas mist drops in the vacuum is reduced to the maximum extent, the content of components similar to washing oil components in the vacuum is greatly reduced, and the circulating washing oil absorbs the components less, so that the pollution to the circulating washing oil is reduced, the quality of the circulating washing oil is effectively ensured, the replacement period of the circulating washing oil is greatly increased, and the strong guarantee is provided for the continuous and stable operation of the vacuum.

2) The vacuum air from the first chamber of the double-chamber reflux tank is cooled by the vacuum cooler, so that the temperature of the vacuum air is reduced to be almost the same as that of the circulating washing oil, and the temperature of the circulating washing oil is hardly increased, so that the temperature of the circulating washing oil is ensured to be stable, the temperature of the circulating washing oil is not influenced due to the high temperature of the vacuum air, and the air suction capacity of the vacuum pump is effectively ensured.

Drawings

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

In the figure: 1-reduced pressure tar distillation tower 2-raw material tar/three-mixed oil heat exchanger 3-three-mixed fraction cooler 4-double-chamber reflux tank 5-reflux pump 6-mist catcher 7-vacuum cyclone catcher 8-vacuum cooler 9-liquid ring vacuum pump 10-gas-liquid separation tank 11-vacuum liquid cooler 12-partition plate 13-regulating valve 14-self-operated regulating valve 41-first chamber 42-second chamber

Detailed Description

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

as shown in figure 1, a vacuum system for a vacuum distillation tower for collecting three-mixed fraction and reducing tar comprises a double-chamber reflux tank 4, a vacuum cyclone catcher 7 and a vacuum cooler 8.

The double-chamber reflux groove 4 is divided into two independent first chamber 41 and second chamber 42 by the clapboard 12, the second chamber 42 is directly connected with the vacuum cyclone catcher 7, the first chamber 41 and the second chamber 42 are connected with the vacuum cooler 8 through pipelines, the vacuum cyclone catcher 7 is connected with the vacuum cooler 8 through pipelines, and the vacuum cyclone catcher 7 is connected with the diffusing system through pipelines. The top of the reduced pressure tar distillation tower 1 is connected with the first chamber 41 through a pipeline, and a raw material tar/three-mixed oil heat exchanger 2 and a three-mixed fraction cooler 3 are arranged on the pipeline connecting the top of the reduced pressure tar distillation tower 1 with the first chamber 41.

The first chamber 41 and the second chamber 42 are both connected with a reflux pump 5 through pipelines, and the reflux pump 5 is connected with the top of the reduced pressure tar distillation tower 1 through a pipeline.

A mist trap 6 is provided on the conduit connecting the chamber 41 to the vacuum cooler 8. A self-operated adjusting valve 14, a liquid ring vacuum pump 9, a vacuum liquid cooler 11 and a gas-liquid separation tank 10 are sequentially arranged on a pipeline connecting the vacuum cyclone catcher 7 and the diffusing system, the liquid ring vacuum pump 9 is connected with the gas-liquid separation tank 10 through a pipeline, and an adjusting valve 13 is arranged on a branch pipeline connecting the vacuum cyclone catcher 7 and the diffusing system.

A vacuum continuous distillation process for collecting three-mixed fraction tar comprises the following steps:

1) the three-mixed oil gas from the top of the reduced pressure tar distillation tower 1 enters a raw material tar/three-mixed oil heat exchanger 2 for condensation and cooling, then enters a three-mixed fraction cooler 3 for cooling, and the three-mixed oil cooled to 80-100 ℃ enters a first chamber 41 of a double-chamber reflux tank 4; the third mixed oil is pumped out by a reflux pump 5, one part of the third mixed oil is sent back to the top of the vacuum tar distillation tower 1, and the other part of the third mixed oil is sent out;

2) vacuum gas at the top of one chamber 41 of the double-chamber reflux tank 4 sequentially passes through a mist catcher 6, a vacuum cooler 8 and a vacuum cyclone catcher 7 and finally enters a liquid ring vacuum pump 9, gas-liquid mixed liquid is sent into a gas-liquid separation tank 10 by the liquid ring vacuum pump 9, gas-liquid separation is carried out at the gas-liquid separation tank, and the gas enters a diffusion system for unified treatment;

the mist catcher 6 catches oil mist carried in high-temperature vacuum air, then the oil mist enters the vacuum cooler 8 for further cooling, the oil mist which is not caught is changed into oil drops, the oil drops automatically flow to the two chambers 42 of the double-chamber backflow groove 4, and the gas enters the vacuum cyclone catcher 7;

gas from the upper part of the vacuum cooler 8 enters a vacuum cyclone catcher 7, the vacuum gas is finally and thoroughly separated from condensed oil mist, the gas is subjected to cyclone separation and then enters a liquid ring vacuum pump 9 from the top of the middle of the vacuum cyclone catcher 7, and oil drops automatically flow to a second chamber 42 of the double-chamber reflux groove 4 along the side wall of the vacuum cyclone catcher 7;

3) washing oil is selected as circulating liquid of a liquid ring vacuum pump 9 for distilling the reduced pressure tar, enters a vacuum liquid cooler 8 from a gas-liquid separation tank 10, is cooled, and then returns to the liquid ring vacuum pump 9 for recycling;

4) the negative pressure at the top of the reduced pressure tar distillation tower 1 is regulated by a gas traffic pipe regulating valve 13 at the inlet and the outlet of a liquid ring vacuum pump 9, and if the vacuum is not condensed and the gas amount is not enough, nitrogen gas is supplemented by a self-operated regulating valve 14.

The condensed oil gas in the vacuum is separated by the mist catcher 6, the vacuum cooler 8 and the vacuum cyclone catcher 7 for three times, the content of condensed gas mist drops in the vacuum is reduced to the maximum extent, the content of components similar to washing oil components in the vacuum is greatly reduced, and the absorption of the circulating washing oil to the components is reduced, so that the pollution to the circulating washing oil is reduced, the quality of the circulating washing oil is effectively ensured, the replacement period of the circulating washing oil is greatly increased, and the strong guarantee is provided for the continuous and stable operation of the vacuum.

The vacuum air from the first chamber 41 of the double-chamber reflux tank 4 is cooled by the vacuum cooler 8, so that the temperature of the vacuum air is reduced to be almost the same as that of the circulating washing oil, and the temperature of the circulating washing oil is hardly increased, thereby ensuring the stable temperature of the circulating washing oil, not influencing the temperature of the circulating washing oil due to the high temperature of the vacuum air, and effectively ensuring the air exhaust capacity of the vacuum pump.

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.