CN114797148A

CN114797148A - Continuous distillation system for synthesis of methyl fluorobenzene

Info

Publication number: CN114797148A
Application number: CN202210598871.2A
Authority: CN
Inventors: 汪峻; 杨国礼; 叶强林
Original assignee: Dongzhi Detai Fine Chemical Co ltd
Current assignee: Dongzhi Detai Fine Chemical Co ltd
Priority date: 2022-05-30
Filing date: 2022-05-30
Publication date: 2022-07-29

Abstract

The invention discloses a continuous distillation system for synthesis of methyl fluorobenzene, which comprises a rectifying tower, wherein the bottom of the rectifying tower is connected with a water distribution tank through a pipeline, the top end of the water distribution tank is fixedly provided with a fixed box, the bottom end of the fixed box extends to the inside of the water distribution tank and is provided with an opening, the top end of the fixed box extends to the outside of the water distribution tank and is fixedly provided with a first air cylinder, and an output shaft of the first air cylinder extends to the inside of the fixed box and is fixedly connected with a support. According to the water distribution tank, water can be sprayed to the interior of the water distribution tank through the high-pressure water gun, so that the inner wall of the water distribution tank can be automatically cleaned, the water distribution tank can be cleaned more conveniently, the poke rod can be driven to vertically move through the second cylinder, the poke rod can slide in the rectangular sliding port to drive the rotating strip to rotate, the angle of the high-pressure water gun can be adjusted, the water spraying range of the high-pressure water gun is larger, the water can be sprayed to the inner wall of the water distribution tank to be cleaned more extensively, and the cleaning range is larger.

Description

Continuous distillation system for synthesis of methyl fluorobenzene

Technical Field

The invention relates to the technical field of methylfluorobenzene synthesis, in particular to a continuous distillation system for methylfluorobenzene synthesis.

Background

In the synthesis process of the methylfluorobenzene, a crude methylfluorobenzene product generated in the synthesis reaction needs to be distilled and purified by a normal-pressure rectifying tower.

In the prior art, the crude material of the methyl fluorobenzene is purified mainly by adopting an intermittent distillation mode, and the defects of long distillation time consumption, high energy consumption and low yield exist.

This scheme adopts the mode of continuous type distillation to come to carry out the distillation purification to methyl fluorobenzene crude through the atmospheric distillation tower, need use the ordinary pressure water knockout drum among the distillation process to the distillation process, because the initial stage of rectifying column driving, the product is extracted unstably, contains the unable direct storage of collecting through the finished product jar of keeping in of more moisture in the adjacent methyl fluorobenzene that collects in the cauldron is accepted to the ordinary pressure this moment.

Disclosure of Invention

The invention provides a continuous distillation system for synthesis of methyl fluorobenzene, which solves the problems in the background technology.

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

a continuous distillation system for methyl fluorobenzene synthesis comprises a rectifying tower and a water distribution tank, and is characterized in that a fixed box is fixedly mounted at the top end of the water distribution tank, the bottom end of the fixed box extends to the inside of the water distribution tank and is provided with an opening, the top end of the fixed box extends to the outside of the water distribution tank and is fixedly provided with a first air cylinder, an output shaft of the first air cylinder extends to the inside of the fixed box and is fixedly connected with a support, a first vertical shaft is mounted at the bottom end of the support, a first installation box is fixedly connected with the bottom end of the first vertical shaft, a second installation box is fixedly connected with the bottom end of the first installation box, a second air cylinder is fixedly mounted in the first installation box, an output shaft of the second air cylinder extends to the inside of the second installation box and is fixedly connected with a connecting frame, two poking rods are fixedly connected to the connecting frame, rotating strips are mounted on two sides of the second installation box, one end of each rotating strip extends to the outside of the second installation box and is fixedly connected with a high-pressure water gun, the other end of the rotating strip extends to the inside of the fixed box and is provided with a rectangular sliding opening, and the two poke rods correspondingly penetrate through the two rectangular sliding openings respectively.

Preferably, the top end of the first vertical shaft is rotatably connected with the support, the bottom end of the support is further fixedly provided with a rotating motor, an output shaft of the rotating motor is fixedly connected with a first gear, a second gear is fixedly arranged on the outer side of the first vertical shaft, and the first gear is meshed with the second gear.

Preferably, the end of intaking of high-pressure squirt is connected with the hose, and the one end that the high-pressure squirt was kept away from to the hose extends to the outside of water diversion tank.

Preferably, a cooling jacket is installed on the outer side of the water distribution tank, and a refrigerant inlet pipe and a refrigerant discharge pipe are connected to the outer side of the cooling jacket.

Preferably, the bottom end of the water distribution tank is provided with a drain pipe.

Preferably, the bottom of second install bin is fixed with the baffle through the connecting rod, and the open matching in bottom of baffle and fixed case, and the top fixedly connected with sealing washer of baffle.

Preferably, a reboiler is installed at the bottom of the rectifying tower, a top extraction pipeline is connected to the top of the rectifying tower, a side extraction pipeline is connected to the side surface of the rectifying tower, and the top extraction pipeline is communicated with the reflux tank through a first condenser.

Preferably, the side extraction pipeline is communicated with the normal pressure receiving kettle through a second condenser, a discharge port of the reflux tank is connected with a reflux branch and a collection branch, and the reflux branch is connected back to the rectifying tower.

Preferably, the collecting branch is connected to the normal pressure receiving kettle, a discharge port of the normal pressure receiving kettle is provided with a water distributor branch and a storage branch, the water distributor branch is communicated with the water distribution tank, and the storage branch is communicated to the finished product temporary storage tank.

The invention has the beneficial effects that:

1. the crude methylfluorobenzene is purified by a continuous distillation mode, so that the yield is higher, the product quality is more stable, the operation is simple, and the energy is saved.

2. The high-pressure water gun can spray water to the interior of the water distribution tank, so that the inner wall of the water distribution tank can be automatically cleaned, the water distribution tank can be cleaned more conveniently, the poke rod can be driven to vertically move through the second air cylinder, the poke rod can slide in the rectangular sliding port to drive the rotating strip to rotate, the angle of the high-pressure water gun can be adjusted, the water spraying range of the high-pressure water gun is larger, the water spraying cleaning can be performed on the inner wall of the water distribution tank in a larger range, and the cleaning range is larger;

3. the rotating motor can drive the first gear to rotate, the first vertical shaft can be driven to rotate through the meshing of the first gear and the second gear, the second installation box is driven to rotate, the high-pressure water gun can move in a rotating mode along with the second installation box, the water spraying range of the second installation box is further increased, the cleaning range is further improved, and no dead angle exists in cleaning.

Drawings

FIG. 1 is a flow chart of a continuous distillation system for the synthesis of fluorobenzene according to the present invention.

Fig. 2 is an enlarged sectional view of a water separation tank of a continuous distillation system for synthesis of methylfluorobenzene according to the present invention.

FIG. 3 is an enlarged view of the position A of the water separation tank of the continuous distillation system for the synthesis of fluorobenzene according to the present invention.

Fig. 4 is an enlarged sectional view of a second installation box of the continuous distillation system for the synthesis of fluorobenzene according to the present invention.

Reference numbers in the figures: 1. a rectifying tower; 2. a first condenser; 3. a second condenser; 4. a reflux tank; 5. a water diversion tank; 6. a normal pressure receiving kettle; 7. a reboiler; 8. a drain pipe; 9. a fixed box; 10. a first cylinder; 11. a support; 12. a first vertical axis; 13. a first installation box; 14. a second installation box; 15. a baffle plate; 16. a seal ring; 17. a rotating electric machine; 18. a first gear; 19. a second gear; 20. a second cylinder; 21. a connecting frame; 22. rotating the strip; 23. a high pressure water gun; 24. a hose; 25. a rectangular sliding port; 26. a poke rod; 27. a cooling jacket; 28. a refrigerant inlet pipe; 29. a refrigerant discharge pipe; 30. and (5) a finished product temporary storage tank.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.

Example 1

Referring to fig. 1-4, a continuous distillation system for methyl fluorobenzene synthesis comprises a rectifying tower 1 and a water diversion tank 5, wherein a reboiler 7 is installed at the bottom of the rectifying tower 1 for heating materials, a top extraction pipeline is connected to the top of the rectifying tower 1, a side extraction pipeline is connected to the side surface of the rectifying tower 1, the top extraction pipeline is communicated with a reflux tank 4 through a first condenser 2, the side extraction pipeline is communicated with a normal pressure receiving kettle 6 through a second condenser 3, a discharge port of the reflux tank 4 is connected with a reflux branch and an acquisition branch, the reflux branch is connected back to the rectifying tower 1, the acquisition branch is connected to the normal pressure receiving kettle 6, the normal pressure receiving kettle 6 is used for collecting purified methyl fluorobenzene, a discharge port of the normal pressure receiving kettle 6 is provided with a water distributor branch and a storage branch, the water distributor branch is communicated with the water diversion tank 5, the storage branch is communicated to a finished product temporary storage tank 30, and at the initial starting stage of the rectifying tower 1, the product extraction is unstable, at the moment, more moisture contained in the o-methylfluorobenzene collected in the normal pressure receiving kettle 6 cannot be directly collected and stored through the finished product temporary storage tank 30, the o-methylfluorobenzene is firstly introduced into the water distribution tank 5, the o-methylfluorobenzene containing more moisture is cooled in the water tank 5 and then stands for layering, the o-methylfluorobenzene is positioned on the upper layer, sewage is positioned on the lower layer of the water distribution tank 5, the sewage can be discharged through a sewage discharge valve at the bottom end of the water distribution tank 5, the purified o-methylfluorobenzene is left in the water distribution tank 5 for collection, and finally the o-methylfluorobenzene is pumped into the finished product temporary storage tank 30, a fixed box 9 is fixedly installed at the top end of the water distribution tank 5, the bottom end of the fixed box 9 extends to the inside of the water distribution tank 5 and is provided with an opening, a first air cylinder 10 is fixedly installed at the top end of the fixed box 9, an output shaft of the first air cylinder 10 extends to the inside of the fixed box 9 and is fixedly connected with a support 11, the bottom end of the bracket 11 is provided with a first vertical shaft 12, the bottom end of the first vertical shaft 12 is fixedly connected with a first installation box 13, the bottom end of the first installation box 13 is fixedly connected with a second installation box 14, a second cylinder 20 is fixedly installed in the first installation box 13, an output shaft of the second cylinder 20 extends into the second installation box 14 and is fixedly connected with a connecting frame 21, two poking rods 26 are fixedly connected on the connecting frame 21, two rotating strips 22 are installed at two sides of the second installation box 14, one end of each rotating strip 22 extends to the outside of the second installation box 14 and is fixedly connected with a high-pressure water gun 23, the other end of each rotating strip 22 extends to the inside of the fixed box 9 and is provided with a rectangular sliding port 25, the two poking rods 26 respectively and correspondingly penetrate through the two rectangular sliding ports 25, the first cylinder 10 extends to drive the high-pressure water gun 23 to move to the outside of the fixed box 9, the first cylinder 10 shortens to drive the high-pressure water gun 23 to be accommodated in the fixed box 9, high-pressure squirt 23 can be to the inside water spray of diversion tank 5, thereby can wash the inner wall of diversion tank 5 automatically, it is more convenient that diversion tank 5 washs, and can drive the vertical removal of poker rod 26 through second cylinder 20, poker rod 26 can drive rotation strip 22 and rotate in rectangle slip mouth 25 slides, thereby can adjust the angle of high-pressure squirt 23, make the water spray scope of high-pressure squirt 23 bigger, thereby can spray water on a wider scale the inner wall of diversion tank 5 and wash, the cleaning range is bigger.

Example 2

Referring to fig. 1 to 4, the embodiment is different from embodiment 1 in that the top end of the first vertical shaft 12 is rotatably connected to the support 11, a rotating motor 17 is further fixedly mounted at the bottom end of the support 11, an output shaft of the rotating motor 17 is fixedly connected to a first gear 18, a second gear 19 is fixedly mounted on the outer side of the first vertical shaft 12, the first gear 18 is meshed with the second gear 19, the rotating motor 17 can drive the first gear 18 to rotate, the first vertical shaft 12 can be driven to rotate by meshing the first gear 18 with the second gear 19, so as to drive the second installation box 14 to rotate, the high-pressure water gun 23 can rotate and move along with the second installation box 14, the range of the second installation box 14 for spraying water is further increased, the cleaning range is further increased, and no dead angle exists in cleaning.

Wherein, the end of intaking of high-pressure squirt 23 is connected with hose 24, and hose 24 keeps away from the one end of high-pressure squirt 23 and extends to the outside of dividing water jar 5, and hose 24 keeps away from high-pressure squirt 23 one end and water tank intercommunication to provide the water of washing usefulness for high-pressure squirt 23.

Wherein, the outside of water diversion tank 5 is installed cooling jacket 27, and the outside of cooling jacket 27 is connected with refrigerant admission pipe 28 and refrigerant discharge pipe 29 for quick cooling to the azeotrope, separation of acceleration water.

Wherein, the drain pipe 8 is installed to the bottom of water distribution tank 5, and the sewage of drain pipe 8 exhaust is sent to the sewage treatment station through the pipeline and is handled the back and discharge.

Wherein, the bottom of second install bin 14 is fixed with baffle 15 through the connecting rod, and baffle 15 and the uncovered matching in bottom of fixed case 9, and the top fixedly connected with sealing washer 16 of baffle 15, when high-pressure squirt 23 accomodates the inside of fixed case 9, baffle 15 can be blocked up uncovered, and sealing washer 16 is used for the shutoff gap, can guarantee the inside complete sealing of fixed case 9.

The working principle is as follows:

the continuous rectification operation extraction amount and the control process parameters are as follows:

1. amount of feed

The feeding pipeline of the rectifying tower 1 is provided with a flowmeter, the feeding flow is set (the design working condition is 250 kg/h)

2. Amount of reflux produced

After the liquid is stored in the reflux tank 4, the total reflux is started, the reflux is started to be extracted when the temperature of the tower top is 115 ℃ (the reflux ratio is designed to be 45), and front fraction fluorobenzene is extracted from the tower top; and simultaneously starting side line extraction, wherein the extraction temperature is 117 ℃, and the product o-methylfluorobenzene is extracted (the designed extraction amount is 220 kg/h).

3. Main technological indexes of rectifying tower

Pressure at the top of the column: 0 to 20KPaG

The tower top temperature: 110-120 DEG C

Liquid temperature under condenser: 45-55 DEG C

Liquid level of the tower kettle: 50 to 85 percent

Liquid level of the reflux tank: 40 to 60 percent

Temperature at the bottom of the column: 120-130 DEG C

The rectifying tower is started for preparation:

1. the inspection equipment has the driving condition, and is connected with the electric equipment, the instrument personnel inspects all the electric equipment, the instrument has the driving condition, the motor quantity of each pump is insulated, the power transmission is carried out, the turning is carried out, the test run is carried out, and the process is matched with each regulating valve to be debugged.

2. And checking whether the public and auxiliary circulating water, the steam and the instrument gas have the driving conditions.

3. And opening circulating water inlet and return valves of the condensers.

4. The regulating valve is set to be in a manual state and is completely closed.

5. And various emergency protection measures, post record reports and shift log books are made.

The method comprises the following steps:

1. and (3) starting a feeding valve of the rectifying tower 1 to feed the rectifying tower 1, starting a steam main valve of a reboiler 7 when the liquid level of a tower kettle reaches 50% -80%, and controlling the opening of a steam regulating valve by DCS operators to slowly introduce steam so as to control the heating rate.

2. And when the liquid level of the tower top reflux tank 4 reaches 30%, starting a reflux pump to establish reflux, and keeping the liquid level of the reflux tank 4 stable within 0.5-1 hour of total reflux.

3. After the total reflux operation is stable, the temperature at the bottom of the tower is not controlled, the temperature at the top of the tower is 113-115 ℃, and the pressure at the top of the tower is 6-10 KPaG; the liquid level of the reflux tank is controlled between 40 percent and 60 percent; the blanking temperature of the condenser is 45-55 ℃.

4. The liquid level of the reflux tank 4 is controlled to be relatively stable, and light components in the product are extracted.

5. The side line temperature (tower internode temperature) is 117 ℃, products are extracted, and after the products are stably extracted, the feeding adjusting valve and the side line extraction adjusting valve are automatically controlled.

A rectifying tower stopping step:

1. the feed was stopped.

2. Closing the tower top and side line extraction, and performing total reflux.

3. The steam is turned off.

First cylinder 10 shortens and to drive high-pressure squirt 23 and accomodate the inside to fixed case 9, high-pressure squirt 23 can spray water to the inside of diversion tank 5, thereby can wash the inner wall of diversion tank 5 automatically, it is more convenient to wash diversion tank 5, and can drive poker rod 26 vertical removal through second cylinder 20, poker rod 26 slides in rectangle slip mouth 25 and can drive rotation strip 22 and rotate, thereby can adjust the angle of high-pressure squirt 23, make the water spray scope of high-pressure squirt 23 bigger, thereby can be on a larger scale carry out the water spray washing to the inner wall of diversion tank 5, the cleaning range is bigger.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used only for convenience of description and simplicity of description, and do not indicate or imply that the equipment or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be considered as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

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.

Claims

1. A continuous distillation system for methyl fluorobenzene synthesis comprises a rectifying tower (1) and a water distribution tank (5), and is characterized in that a fixed box (9) is fixedly mounted at the top end of the water distribution tank (5), the bottom end of the fixed box (9) extends to the inside of the water distribution tank (5) and is provided with an opening, a first air cylinder (10) is fixedly mounted at the top end of the fixed box (9) and extends to the outside of the water distribution tank (5), an output shaft of the first air cylinder (10) extends to the inside of the fixed box (9) and is fixedly connected with a support (11), a first vertical shaft (12) is mounted at the bottom end of the support (11), a first mounting box (13) is fixedly connected at the bottom end of the first vertical shaft (12), a second mounting box (14) is fixedly connected at the bottom end of the first mounting box (13), a second air cylinder (20) is fixedly mounted in the first mounting box (13), and a connecting frame (21) is fixedly connected at the output shaft of the second air cylinder (20) extends to the second mounting box (14), two poking rods (26) fixedly connected with are arranged on the connecting frame (21), the rotating strips (22) are installed on two sides of the second installation box (14), one ends of the rotating strips (22) extend to the outside of the second installation box (14) and the fixedly connected high-pressure water gun (23), the other ends of the rotating strips (22) extend to the inside of the fixed box (9) and rectangular sliding openings (25) are formed, and the two poking rods (26) correspondingly penetrate through the two rectangular sliding openings (25) respectively.

2. The continuous distillation system for synthesis of fluorobenzene according to claim 1, wherein the top end of the first vertical shaft (12) is rotatably connected with the support (11), the bottom end of the support (11) is further fixedly provided with a rotating motor (17), an output shaft of the rotating motor (17) is fixedly connected with a first gear (18), a second gear (19) is fixedly arranged on the outer side of the first vertical shaft (12), and the first gear (18) is meshed with the second gear (19).

3. The continuous distillation system for synthesis of fluorobenzene according to claim 1, wherein a hose (24) is connected to a water inlet end of the high-pressure water gun (23), and one end of the hose (24) far away from the high-pressure water gun (23) extends to the outside of the water diversion tank (5).

4. The continuous distillation system for synthesis of fluorobenzene according to claim 1, wherein a cooling jacket (27) is installed outside the water separation tank (5), and a refrigerant inlet pipe (28) and a refrigerant outlet pipe (29) are connected to the outside of the cooling jacket (27).

5. The continuous distillation system for the synthesis of fluorobenzene according to claim 1, wherein a drain pipe (8) is installed at the bottom end of the water separation tank (5).

6. The continuous distillation system for the synthesis of fluorobenzene according to claim 1, wherein a baffle (15) is fixed at the bottom end of the second installation box (14) through a connecting rod, the baffle (15) is matched with the bottom end opening of the fixed box (9), and a sealing ring (16) is fixedly connected to the top end of the baffle (15).

7. The continuous distillation system for the synthesis of fluorobenzene according to claim 1, wherein the reboiler (7) is installed at the bottom of the rectifying tower (1), a top extraction pipeline is connected to the top of the rectifying tower (1), a side extraction pipeline is connected to the side surface of the rectifying tower (1), and the top extraction pipeline is communicated with the reflux tank (4) through the first condenser (2).

8. The continuous distillation system for the synthesis of the fluorobenzene according to claim 7, wherein the side extraction pipeline is communicated with the normal pressure receiving kettle (6) through the second condenser (3), the discharge port of the reflux tank (4) is connected with a reflux branch and a collection branch, and the reflux branch is connected back to the rectifying tower (1).

9. The continuous distillation system for synthesis of fluorobenzene according to claim 8, wherein the collection branch is connected to an atmospheric pressure receiving kettle (6), a discharge port of the atmospheric pressure receiving kettle (6) is provided with a water separator branch and a storage branch, the water separator branch is communicated with the water separation tank (5), and the storage branch is communicated to a finished product temporary storage tank (27).