阅读说明：本技术 一种偏苯三酸酐精馏塔釜残液中偏苯三酸酐的回收装置和方法 (Device and method for recovering trimellitic anhydride from residual liquid in trimellitic anhydride rectifying tower kettle ) 是由 蒋国强 孙百亚 夏海峰 吴晓明 赵跃 周国君 万鹏 梁国成 张晓� 于 2020-06-24 设计创作，主要内容包括：本发明涉及物料回收领域,具体公开了一种偏苯三酸酐精馏塔釜残液中偏苯三酸酐的回收装置和方法,包括回收釜、偏苯三酸酐精馏塔、残液收集釜、精馏塔冷凝器、氮气储罐、低温油罐、热油炉和真空泵,将偏苯三酸酐精馏塔残液打入回收釜内将偏苯三酸酐蒸馏提出再回收,本发明回收釜内有足够时间可以把偏苯三酸酐精馏塔残液中偏苯三酸酐进行回收,两台回收釜切换使用使运行更加平稳、高效,不仅有效提高偏苯三酸酐回收率,增加产品得率,还可以减少固废产生,大大减轻固废处理压力,更加符合环保相关要求。(The invention relates to the field of material recovery, and particularly discloses a device and a method for recovering trimellitic anhydride in trimellitic anhydride rectifying tower residual liquid, which comprises a recovery kettle, a trimellitic anhydride rectifying tower, a residual liquid collection kettle, a rectifying tower condenser, a nitrogen storage tank, a low-temperature oil tank, a hot oil furnace and a vacuum pump, wherein the residual liquid of the trimellitic anhydride rectifying tower is pumped into the recovery kettle to distill and extract the trimellitic anhydride for recovery.)

1. A recovery unit of trimellitic anhydride in trimellitic anhydride rectifying column cauldron raffinate which characterized in that: comprises a recovery kettle (20), a trimellitic anhydride rectifying tower (27), a residual liquid collecting kettle (21), a rectifying tower condenser (22), a nitrogen storage tank (23), a low-temperature oil tank (24), a hot oil furnace (25) and a vacuum pump (26),

the upper end of the recovery kettle (20) is provided with a gaseous trimellitic anhydride outlet (1), a residual liquid feed inlet (2), a vacuumizing port (3) and a nitrogen filling gas port (4), the right side of the recovery kettle (20) is sequentially provided with a heat conduction oil inlet (5) and a cold conduction oil inlet (6) from top to bottom, the left side of the recovery kettle (20) is sequentially provided with a heat conduction oil outlet (7) and a cold conduction oil outlet (8) from top to bottom, and the lower end of the recovery kettle (20) is provided with a slag discharge port (9);

the gaseous trimellitic anhydride outlet (1) is connected with the rectifying tower condenser (22);

the residual liquid feeding hole (2) is connected with a residual liquid collecting kettle (21), the residual liquid collecting kettle (21) is connected with the lower part of the trimellitic anhydride rectifying tower (27), and the upper part of the trimellitic anhydride rectifying tower (27) is connected with the rectifying tower condenser (22);

the vacuum pumping port (3) is connected with the vacuum pump (26);

the nitrogen charging port (4) is connected with the nitrogen storage tank (23);

the heat conduction oil inlet (5) is connected with an outlet of the hot oil furnace (25), and the heat conduction oil outlet (7) is connected with an inlet of the hot oil furnace (25);

the cold guide oil inlet (6) is connected with an outlet of the low-temperature oil tank (24), and the cold guide oil outlet (8) is connected with an inlet of the low-temperature oil tank (24);

the slag discharge port (9) is connected with a waste slag receiver;

and a stirring motor (10) is arranged in the recovery kettle.

2. The device for recovering trimellitic anhydride from trimellitic anhydride rectification column bottom residual liquid according to claim 1, characterized in that a recovery column gas phase cut-off valve (11) is arranged on a connecting pipeline between the gaseous trimellitic anhydride outlet (1) and the rectification column condenser (22).

3. The device for recovering trimellitic anhydride from trimellitic anhydride rectification column bottoms according to claim 1, wherein a feed valve (12) is arranged on a connecting pipeline between the residual liquid feed inlet (2) and the residual liquid collection kettle (21).

4. The device for recovering trimellitic anhydride from trimellitic anhydride rectification column residue according to claim 1, wherein a vacuum-pumping valve (13) is arranged on a connecting pipeline between the vacuum-pumping port (3) and the vacuum pump (26).

5. The device for recovering trimellitic anhydride from trimellitic anhydride rectification column residue according to claim 1, characterized in that a nitrogen filling valve (14) is arranged on a connecting pipeline between the nitrogen filling port (4) and the nitrogen storage tank (23).

6. The device for recovering trimellitic anhydride from trimellitic anhydride rectifying tower residual liquid according to claim 1, characterized in that a conduction oil inlet valve (15) is arranged on a connecting pipeline between the conduction oil inlet (5) and an outlet of the hot oil furnace (24), and a conduction oil outlet valve (17) is arranged on a connecting pipeline between the conduction oil outlet (7) and the inlet of the hot oil furnace (24).

7. The device for recovering trimellitic anhydride from trimellitic anhydride rectification column bottoms according to claim 1, wherein a cold-conducting oil inlet valve (16) is arranged on a connecting pipeline between the cold-conducting oil inlet (6) and the outlet of the low-temperature oil tank (24), and a cold-conducting oil outlet valve (18) is arranged on a connecting pipeline between the cold-conducting oil outlet (8) and the inlet of the low-temperature oil tank (24).

8. The device for recovering trimellitic anhydride from trimellitic anhydride rectification column residue according to claim 1, characterized in that a discharge valve (19) is arranged on a connecting pipeline between the slag discharge port (9) and the waste residue receiver.

9. The device for recovering trimellitic anhydride from trimellitic anhydride rectification column residue according to claims 1-8, characterized in that the number of the recovery kettles (20) is two, and the two recovery kettles (20) are connected in parallel to a discharge port of a residue collection kettle (21).

10. A method for recovering trimellitic anhydride from trimellitic anhydride rectification tower residual liquid is characterized in that the recovery device for the trimellitic anhydride from the trimellitic anhydride rectification tower residual liquid is adopted to recover the trimellitic anhydride from the trimellitic anhydride rectification tower residual liquid according to any one of claims 1 to 9, and the method comprises the following steps: the recovery method comprises the following process steps:

the method comprises the following steps: checking whether the feeding valve (12) is closed, and performing the next step after confirming the closing;

step two: opening a vacuumizing valve (13), observing whether the pressure of the recovery kettle is reduced, opening a heat conduction oil inlet valve (15) and a heat conduction oil outlet valve (17), and preheating the recovery kettle (20);

step three: when the pressure is reduced to-0.085 to-0.095 MPA and the temperature is increased to 260 to 280 degrees, closing the vacuumizing valve (13), the heat-conducting oil inlet valve (15) and the heat-conducting oil outlet valve (17) for later use;

step four: opening a feeding valve (12), discharging materials into the recovery kettle (20), closing the feeding valve (12) after the materials are discharged, and starting a stirring motor (10);

step five: after the stirring motor (10) operates stably, opening a vacuum pumping valve (13), opening a gas phase cut-off valve (11) of the recovery kettle, opening a heat conduction oil inlet valve (15) and a heat conduction oil outlet valve (17), and operating stably for four hours;

step six: after four hours of operation, closing the vacuumizing valve (13), closing the heat-conducting oil inlet valve (15) and the heat-conducting oil outlet valve (17), and closing the gas phase cut-off valve (11) of the recovery kettle;

step seven: opening a cold guiding oil inlet valve (6) and a cold guiding oil outlet valve (8), and closing the cold guiding oil inlet valve (6) and the cold guiding oil outlet valve (8) when the temperature of the recovery kettle is slowly reduced to 200 ℃;

step eight: opening a nitrogen filling valve (14), and closing the nitrogen filling valve (14) when the pressure of the recovery kettle is increased to 0.04-0.06 MPA;

step nine: opening a discharge valve (19), and closing the discharge valve (19) after the residual liquid in the recovery kettle is discharged;

step ten: the recovery kettle (20) repeats the actions from the first step to the ninth step and recovers the residual liquid of the next batch;

eleven, after one of the two recovery kettles (20) stably operates for two hours, the other of the two recovery kettles (20) starts to operate, and the operation process from the first step to the tenth step is repeated.

Technical Field

The invention relates to the field of material recovery, in particular to a device and a method for recovering trimellitic anhydride from residual liquid in a trimellitic anhydride rectifying tower.

Background

At present, in the continuous rectification process of a trimellitic anhydride rectification tower, the temperature of a tower kettle is higher and higher, the residual liquid in the tower kettle needs to be discharged intermittently, and otherwise, the production efficiency of the rectification tower is influenced. After the residual liquid is discharged, the residual liquid is not effectively distilled, so that a large amount of trimellitic anhydride contained in the residual liquid cannot be effectively recovered, the yield of the trimellitic anhydride is reduced, and the residual liquid in a tower kettle is condensed into solid at normal temperature to additionally generate a large amount of solid waste, so that the economic benefit is influenced, and the environment is also influenced to a certain extent.

In view of the above situation, a new recovery method is needed to recover trimellitic anhydride in the bottom liquid of the rectification tower as much as possible, increase the product yield and reduce the generation of solid wastes.

Disclosure of Invention

The invention aims to solve the technical problems of reducing the content of trimellitic anhydride in the residual liquid of the trimellitic anhydride rectifying tower, increasing the yield of trimellitic anhydride and reducing the generation of solid wastes.

In order to solve the technical problem, the invention provides a device for recovering trimellitic anhydride from residual liquid in a trimellitic anhydride rectifying tower kettle, which comprises a recovery kettle, a trimellitic anhydride rectifying tower, a residual liquid collection kettle, a rectifying tower condenser, a nitrogen storage tank, a low-temperature oil tank, a hot oil furnace and a vacuum pump,

the upper end of the recovery kettle is provided with a gaseous trimellitic anhydride outlet, a residual liquid feed inlet, a vacuumizing port and a nitrogen filling port, the right side of the recovery kettle is sequentially provided with a heat conduction oil inlet and a cold conduction oil inlet from top to bottom, the left side of the recovery kettle is sequentially provided with a heat conduction oil outlet and a cold conduction oil outlet from top to bottom, and the lower end of the recovery kettle is provided with a slag discharge port;

the outlet of the gaseous trimellitic anhydride is connected with the condenser of the rectifying tower;

the residual liquid feeding hole is connected with a residual liquid collecting kettle, the residual liquid collecting kettle is connected with the lower part of the trimellitic anhydride rectifying tower, and the upper part of the trimellitic anhydride rectifying tower is connected with the rectifying tower condenser;

the vacuum pumping port is connected with the vacuum pump;

the nitrogen charging port is connected with the nitrogen storage tank;

the heat-conducting oil inlet is connected with the outlet of the hot oil furnace, and the heat-conducting oil outlet is connected with the inlet of the hot oil furnace;

the cold guide oil inlet is connected with an outlet of the low-temperature oil tank, and the cold guide oil outlet is connected with an inlet of the low-temperature oil tank;

the slag discharge port is connected with a waste slag receiver;

and a stirring motor is arranged in the recovery kettle.

Further, a gas phase cut-off valve of a recovery kettle is arranged on a connecting pipeline between the outlet of the gaseous trimellitic anhydride and the condenser of the rectifying tower.

And furthermore, a feeding valve is arranged on a connecting pipeline between the residual liquid feeding hole and the residual liquid collecting kettle.

Furthermore, a vacuum pumping valve is arranged on a connecting pipeline between the vacuum pumping port and the vacuum pump.

Furthermore, a nitrogen charging valve is arranged on a connecting pipeline between the nitrogen charging port and the nitrogen storage tank.

Furthermore, a heat conduction oil inlet valve is arranged on a connecting pipeline between the heat conduction oil inlet and the outlet of the hot oil furnace, and a heat conduction oil outlet valve is arranged on a connecting pipeline between the heat conduction oil outlet and the inlet of the hot oil furnace.

Furthermore, a cold oil guiding inlet valve is arranged on a connecting pipeline between the cold oil guiding inlet and the outlet of the low-temperature oil tank, and a cold oil guiding outlet valve is arranged on a connecting pipeline between the cold oil guiding outlet and the inlet of the low-temperature oil tank.

Furthermore, a discharge valve is arranged on a connecting pipeline between the slag discharge port and the waste slag receiver.

Furthermore, the number of the recovery kettles is two, and the two recovery kettles are connected in parallel to a discharge hole of the residual liquid collection kettle.

A method for recovering trimellitic anhydride from trimellitic anhydride rectifying tower residual liquid adopts a recovery device for recovering trimellitic anhydride from trimellitic anhydride rectifying tower residual liquid, and the recovery method comprises the following process steps:

the method comprises the following steps: checking whether the feeding valve is closed, and performing the next step after confirming the closing;

step two: opening a vacuumizing valve, observing whether the pressure of the recovery kettle is reduced, opening a heat conduction oil inlet valve and a heat conduction oil outlet valve, and preheating the recovery kettle;

step three: when the pressure is reduced to-0.085 to-0.095 MPA and the temperature is increased to 260 to 280 degrees, closing the vacuumizing valve, the heat-conducting oil inlet valve and the heat-conducting oil outlet valve for later use;

step four: opening a feeding valve, discharging materials into the recovery kettle, closing the feeding valve after the materials are discharged, and starting a stirring motor;

step five: after the stirring motor operates stably, opening a vacuumizing valve, opening a gas phase cut-off valve of the recovery kettle, opening a heat conduction oil inlet valve and a heat conduction oil outlet valve, and operating stably for four hours;

step six: after four hours of operation, closing the vacuumizing valve, closing the heat-conducting oil inlet valve and the heat-conducting oil outlet valve, and closing the gas phase cut-off valve of the recovery kettle;

step seven: opening a cold guiding oil inlet valve and a cold guiding oil outlet valve, and closing the cold guiding oil inlet valve and the cold guiding oil outlet valve when the temperature of the recovery kettle slowly decreases to 200 ℃;

step eight: opening a nitrogen filling valve, and closing the nitrogen filling valve when the pressure of the recovery kettle is increased to 0.04-0.06 MPA;

step nine: opening a discharge valve, and closing the discharge valve after discharging residual liquid in the recovery kettle;

step ten: the recovery kettle repeats the actions from the first step to the ninth step, and the next batch of residual liquid is recovered;

and step eleven, after one of the two recovery kettles stably runs for two hours, the other one of the two recovery kettles starts to run, and the operation process from the step one to the step ten is repeated.

After the recovery is finished, the content of trimellitic anhydride in the residual liquid collection kettle is lower than 5 percent, and the recovery is qualified; more than 15% of trimellitic anhydride can be recovered in each residual liquid collection kettle, and solid waste of more than 150KG is reduced.

The invention has the advantages that:

1. the recovery kettle has enough time to recover the trimellitic anhydride in the residual liquid of the trimellitic anhydride rectifying tower, so that the recovery rate of the trimellitic anhydride can be effectively improved, and the product yield is increased.

2. The recycling kettle is additionally stirred, so that the residual liquid can be fully mixed, and the recycling efficiency is improved.

3. The recovery kettle is switched to use by two machines, so that the device is more stable and efficient to operate.

4. Can reduce the generation of solid waste, greatly reduce the pressure of solid waste treatment and better meet the relevant requirements of environmental protection.

Drawings

In order to more clearly illustrate the technical solution of the present invention, the drawings needed for the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

FIG. 1 is a schematic view showing the structure of recovering trimellitic anhydride from the residual liquid in the bottom of a trimellitic anhydride rectifying tower according to the present invention;

in the figure: 1-a gaseous trimellitic anhydride outlet, 2-a residual liquid feed inlet, 3-a vacuum pumping port, 4-a nitrogen charging port, 5-a heat transfer oil inlet, 6-a cold guiding oil inlet, 1-a recycling kettle one feed valve, 2-a stirring motor, 3-a vacuum pumping valve, 4-a nitrogen charging valve, 5-a recycling kettle one, 6-a heat transfer oil, 7-a heat transfer oil outlet, 8-a cold guiding oil outlet, 9-a slag discharging port, 10-a stirring motor, 11-a recycling kettle gas phase cut-off valve, 12-a feed valve, 13-a vacuum pumping valve, 14-a nitrogen charging valve, 15-a heat transfer oil inlet valve, 16-a cold guiding oil inlet valve, 17-a heat transfer oil outlet valve, 18-a cold guiding oil outlet valve, 19-a discharging valve and 20-a recycling kettle, 21-a residual liquid collecting kettle, 22-a rectifying tower condenser, 23-a nitrogen storage tank, 24-a low-temperature oil tank, 25-a hot oil furnace, 26-a vacuum pump and 27-a trimellitic anhydride rectifying tower.

Detailed Description

The following describes the specific embodiments of the present invention with reference to examples, so that the technical solutions and the advantages thereof are more clear and clear. The following described embodiments are exemplary and are intended to be illustrative of the invention, but are not to be construed as limiting the invention.