Dimethyl phosphite rectification device

Abstract

The utility model discloses a dimethyl phosphite rectifying device which comprises a rectifying still, a rectifying tower, a condensing device and a distributor, wherein the rectifying still is provided with a dual-heating structure, the top of the rectifying still is connected with a crude ester feeding pipeline, the bottom of the rectifying still is connected with a residual liquid tank, and the upper part of the rectifying still is connected with the rectifying tower through a first gas phase pipeline; the top of the rectifying tower is connected with a condensing device through a second gas phase pipeline, a condensate extraction pipeline is connected below the condensing device and connected with a distributor, the distributor is connected with a backflow pipeline and a refined ester extraction pipeline, the backflow pipeline is connected with a rectifying tower body, and the refined ester extraction pipeline is connected with a transfer tank. The transfer tank is connected with a vacuum device and a finished product tank, and a refined ester content analysis device is arranged on the refined ester extraction pipeline; in general, the rectification device has the advantages of high rectification efficiency, good finished product quality, convenience in remote control and analysis, safety and convenience.

Description

Technical Field

[0001] The utility model belongs to the technical field of dimethyl phosphite production, and specifically relates to a dimethyl phosphite rectification device. Background Art

[0002] Dimethyl phosphite is an important product in fine chemicals. It is an intermediate in the production of pesticides such as glyphosate, trichlorfon, chlorpyrifos, and omethoate, and is also a raw material for organophosphorus corrosion inhibitors, dye additives, plastic additives, and flame retardants. It can be used to synthesize water treatment agents and can also be used as a methylating agent to synthesize quaternary ammonium salts of fungicides, antistatic agents, softeners, and other products.

[0003] With the rise of the domestic herbicide industry, the production of glyphosate is also increasing. The demand for dimethyl phosphite, which is the raw material for producing glyphosate, is also increasing, and the quality requirements are becoming higher and higher. At present, the most commonly used method for the industrial synthesis of dimethyl phosphite in China is to use methanol and phosphorus trichloride as raw materials and synthesize it under certain conditions. It is relatively simple and easy to operate. In the production process of dimethyl phosphite, the crude ester produced needs to be purified and distilled to produce dimethyl phosphite with higher purity.

[0004] However, in the actual production process, the crude ester distillation process is relatively complicated, the temperature control is poor, and there are many impurities. In addition, the current distillation towers mostly use two layers of fillers, and the purity of the produced dimethyl phosphite refined ester is far from meeting the requirements. In particular, it is more difficult to produce refined esters with a content of more than 98%. It is also lacking in analytical testing and remote control, on-site production automation and intelligence, and has low efficiency. Manual sampling and analysis are often required, and the quality of the finished product is not high.

[0005] Therefore, in order to solve the above problems, it is necessary to develop a dimethyl phosphite distillation device. Utility Model Content

[0006] The purpose of the utility model is to overcome the deficiencies of the prior art and to provide a dimethyl phosphite distillation device, which distills crude dimethyl phosphite to produce refined dimethyl phosphite, effectively improving the distillation efficiency and product quality, and can perform remote control analysis, which is safer and more convenient.

[0007] The object of the present utility model is achieved as follows: A dimethyl phosphite rectification device includes a rectification kettle, a rectification tower, a condensation device and a distributor; wherein, a dual heating structure is provided on the rectification kettle, a crude ester feed pipe is connected to the crude ester feed port at the top of the rectification kettle, a residue tank is connected to the discharge port at the bottom of the rectification kettle, and the gas phase outlet directly above the rectification kettle is connected to the gas phase inlet at the bottom of the rectification tower through a first gas phase pipe; the gas phase outlet at the top of the rectification tower is connected to the gas phase inlet of the condensation device through a second gas phase pipe, a condensate extraction pipe is connected to the extraction port below the condensation device, the condensate extraction pipe is connected to the distributor, the reflux port and the refined ester extraction port on the distributor are respectively connected to a reflux pipe and a refined ester extraction pipe, the reflux pipe is connected to the reflux ports in the middle and at the top of the rectification tower body, the refined ester extraction pipe is connected to an intermediate tank, the intermediate tank is connected to a vacuum device and a finished product tank, and a refined ester content analysis device is provided on the refined ester extraction pipe.

[0008] Further, the dual heating structure on the rectification kettle specifically includes: a steam coil disposed inside the rectification kettle, and both ends of the steam coil extend out of the top of the rectification kettle and are connected to a first steam inlet pipe and a first steam outlet pipe; and a jacket disposed outside the rectification kettle, and the jacket is respectively communicated with a second steam inlet pipe and a second steam outlet pipe provided on the side of the rectification kettle body.

[0009] Further, an online thermometer, an online pressure gauge and a radar level gauge are provided on the rectification kettle.

[0010] Further, two observation ports and a maintenance port equipped with explosion-proof glass are provided on the rectification kettle.

[0011] Further, liquid flow meters and control valves are provided on the crude ester feed pipe, the reflux pipe and the refined ester extraction pipe.

[0012] Further, the rectification tower body is divided into three sections, which are connected by flanges, gaskets and grid plates are provided in the middle, and ceramic Raschig ring packings are provided in each section of the tower body.

[0013] Further, the rectification tower body is made of 316 stainless steel, and heat-insulating cotton is provided outside the tower body.

[0014] Further, the condensation device adopts two series-connected tubular, horizontal 316 stainless steel condensers.

[0015] Further, a vacuum device is connected above the condensation device, and heat-insulating cotton is provided outside the condensation device.

[0016] Furthermore, it also includes a remote control system, which is respectively connected to the rectifying still, the rectifying column, the condensing device, the distributor, the vacuum device, as well as the in-line thermometer, the in-line pressure gauge, the radar level gauge, the liquid flowmeter and the control valve; the remote control system adopts a DCS computer control system.

[0017] The beneficial effects of the present utility model are as follows:

[0018] (1) By connecting the rectifying still and the rectifying column in series as the main body for rectifying and purifying the crude ester, the production efficiency is high, the product quality is good and the impurities are few; at the same time, the rectifying still adopts a double steam heating structure to heat the incoming crude ester, with higher heating efficiency, effectively improving the rectifying efficiency and quality;

[0019] (2) By arranging an analysis device for the refined ester content on the refined ester extraction pipeline, the quality of the refined ester finished product after rectifying and purifying can be monitored in real time, reducing the operation of manual sampling and analysis, and when the finished product quality is unqualified, the material is returned to the rectifying column for circulation, effectively ensuring the finished product quality;

[0020] (3) By arranging a distributor, it is convenient to evenly distribute the reflux liquid to the rectifying column, improving the rectifying effect, facilitating rectifying separation and purification, enhancing the continuity of separation and purification, and accelerating the rectifying efficiency;

[0021] Generally, the present utility model has the advantages of high rectifying efficiency, good finished product quality, convenient remote control and analysis, safety and convenience. Description of the Drawings

[0022] Figure 1 is the front view structural schematic diagram of the present utility model.

[0023] Figure 2 is the structural schematic diagram of the rectifying still in the present utility model.

[0024] In the figure: 1, rectifying still; 2, rectifying column; 3, condensing device; 4, distributor; 5, residue tank; 6, transfer tank; 7, vacuum device; 8, finished product tank; 9, analysis device for refined ester content;

[0025] 101, steam coil; 102, first steam inlet pipe; 103, first steam outlet pipe; 104, interlayer; 105, second steam inlet pipe; 106, second steam outlet pipe;

[0026] 01, crude ester feed pipe; 02, first gas phase pipe; 03, second gas phase pipe; 04, condensate extraction pipe; 05, reflux pipe; 06, refined ester extraction pipe;

[0027] a, in-line thermometer; b, in-line pressure gauge; c, radar level gauge; d, liquid flowmeter; e, control valve. Detailed implementation mode

[0028] The technical solution of the present utility model will be further specifically described below in conjunction with the accompanying drawings.

[0029] As Figure 1 、 Figure 2 shown, a dimethyl phosphite rectification device includes a rectification kettle 1, a rectification column 2, a condensation device 3 and a distributor 4.

[0030] Among them, a crude ester feed pipe 01 is connected to the top crude ester feed port of the rectification kettle 1, a residue tank 5 is connected to the bottom discharge port of the rectification kettle 1, the gas phase outlet directly above the rectification kettle 1 is connected to the bottom gas phase inlet of the rectification column 2 through a first gas phase pipe 02, the gas phase outlet at the top of the rectification column 2 is connected to the gas phase inlet of the condensation device 3 through a second gas phase pipe 03, the extraction port below the condensation device 3 is connected to a condensate extraction pipe 04, and the condensate extraction pipe 04 is connected to the distributor 4.

[0031] Among them, a reflux pipe 05 and a refined ester extraction pipe 06 are respectively connected to the reflux port and the refined ester extraction port on the distributor 4, the reflux pipe 05 is connected to the reflux ports in the middle and at the top of the rectification column 2, the refined ester extraction pipe 06 is connected to a transfer tank 6, the transfer tank 6 is connected to a vacuum device 7 and a finished product tank 8, and a refined ester content analysis device 9 is provided on the refined ester extraction pipe 06.

[0032] Specifically, the rectification kettle 1 includes a kettle cover and a kettle body, the kettle cover and the kettle body are fixedly connected by bolts with gaskets in between, the kettle cover and the kettle body can specifically be made of 316 stainless steel, and heat preservation measures are provided on the kettle body; two observation ports and a maintenance port equipped with explosion-proof glass are provided on the rectification kettle 1, and a bright lamp is installed above one of the observation ports for facilitating the observation of the situation inside the kettle.

[0033] Specifically, the rectification kettle 1 is provided with a double heating structure, and the double heating structure specifically includes: a steam coil 101 arranged inside the rectification kettle 1, both ends of the steam coil 101 respectively extend out of the top of the rectification kettle 1 and are connected to a first steam inlet pipe 102 and a first steam outlet pipe 103; and a sandwich layer 104 arranged outside the rectification kettle 1, the sandwich layer 104 is respectively communicated with a second steam inlet pipe 105 and a second steam outlet pipe 106 arranged on the side of the kettle body of the rectification kettle 1; preferably, the first steam inlet pipe 102, the first steam outlet pipe 103, the second steam inlet pipe 105 and the second steam outlet pipe 106 can be made of carbon steel, and gas flow meters and control valves are provided on all of them, and the rectification kettle 1 is heated doubly by introducing steam into both the steam coil 101 and the sandwich layer 104 to improve the heating efficiency.

[0034] Preferably, an on-line thermometer a, an on-line pressure gauge b, and a radar level gauge c are further provided on the rectification still 1, which can detect the working conditions inside the rectification still 1 and have a remote transmission function, and the detection results are transmitted to the remote control system.

[0035] Specifically, the tower body of the rectification column 2 is divided into three sections, which are connected by flanges, with gaskets and grid plates arranged in the middle. Ceramic Raschig rings are arranged in each section of the tower body. The tower body of the rectification column 2 is made of 316 stainless steel, and heat-insulating cotton is arranged outside the tower body.

[0036] Specifically, the condensation device 3 adopts two tube-type, horizontal 316 stainless steel condensers connected in series to improve the condensation effect. A vacuum device 7 is connected above the condensation device 3, and heat-insulating cotton is arranged outside the condensation device 3.

[0037] Preferably, liquid flow meters d and control valves e are provided on the crude ester feed pipeline 01, the reflux pipeline 05, and the refined ester extraction pipeline 06.

[0038] Among them, a remote control system is further included. The remote control system is respectively connected to the rectification still 1, the rectification column 2, the condensation device 3, the distributor 4, and the vacuum device 7, as well as the line thermometer, the on-line pressure gauge b, the radar level gauge c, the liquid flow meter d, and the control valve e. Preferably, the remote control system can adopt a DCS computer control system.

[0039] The above is only the preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A dimethyl phosphite distillation device, characterized in that: It comprises a distillation kettle (1), a distillation tower (2), a condensing device (3) and a distributor (4); The distillation kettle (1) is provided with a dual heating structure, the crude ester feed port at the top of the distillation kettle (1) is connected to a crude ester feed pipeline (01), the discharge port at the bottom of the distillation kettle (1) is connected to a residual liquid tank (5), the gas phase outlet directly above the distillation kettle (1) is connected to the gas phase inlet at the bottom of the distillation tower (2) through a first gas phase pipeline (02); the gas phase outlet at the top of the distillation tower (2) is connected to the gas phase inlet of the condensing device (3) through a second gas phase pipeline (03), and the extraction port below the condensing device (3) is connected to a condensing tank (5). The condensate extraction pipeline (04) is connected to a distributor (4), the reflux port and the refined ester extraction port on the distributor (4) are respectively connected to a reflux pipeline (05) and a refined ester extraction pipeline (06), the reflux pipeline (05) is connected to the reflux ports in the middle and top of the distillation tower (2), the refined ester extraction pipeline (06) is connected to a transfer tank (6), the transfer tank (6) is connected to a vacuum device (7) and a finished product tank (8), and a refined ester content analysis device (9) is arranged on the refined ester extraction pipeline (06).

2. A dimethyl phosphite distillation device according to claim 1, characterized in that: The dual heating structure on the distillation kettle (1) specifically comprises: a steam coil (101) arranged inside the distillation kettle (1), the two ends of the steam coil (101) respectively extending out of the top of the distillation kettle (1) and connected to a first steam inlet pipe (102) and a first steam outlet pipe (103); and an interlayer (104) arranged outside the distillation kettle (1), the interlayer (104) respectively communicating with a second steam inlet pipe (105) and a second steam outlet pipe (106) arranged on the side of the kettle body of the distillation kettle (1).

3. A dimethyl phosphite distillation device according to claim 1, characterized in that: The distillation kettle (1) is provided with an online thermometer (a), an online pressure gauge (b) and a radar level gauge (c).

4. A dimethyl phosphite distillation device according to claim 1, characterized in that: The distillation kettle (1) is provided with two observation ports and an inspection port equipped with explosion-proof glass.

5. A dimethyl phosphite distillation device according to claim 1, characterized in that: The crude ester feed pipeline (01), the reflux pipeline (05), and the refined ester extraction pipeline (06) are all provided with a liquid flow meter (d) and a control valve (e).

6. A dimethyl phosphite distillation device according to claim 1, characterized in that: The distillation tower (2) has a tower body divided into three sections, which are connected to each other by flanges, with gaskets and grid plates arranged in the middle, and ceramic tower ring packing is arranged in each tower body section.

7. A dimethyl phosphite distillation device according to claim 1, characterized in that: The distillation tower (2) has a tower body made of 316 stainless steel, and a heat-insulating cotton is arranged on the outside of the tower body.

8. A dimethyl phosphite distillation device according to claim 1, characterized in that: The condensing device (3) uses two tubular, horizontal 316 stainless steel condensers connected in series.

9. A dimethyl phosphite distillation device according to claim 1, characterized in that: The condensing device (3) is connected to a vacuum device (7) above, and thermal insulation cotton is arranged outside the condensing device (3).

10. A dimethyl phosphite distillation device according to any one of claims 1 to 9, characterized in that: The invention also includes a remote control system, which is respectively connected to the distillation kettle (1), the distillation tower (2), the condensing device (3), the distributor (4) and the vacuum device (7) as well as the online thermometer, the online pressure gauge (b), the radar level meter (c), the liquid flow meter (d) and the control valve (e); the remote control system adopts a DCS computer control system.

Images