CN217490771U

CN217490771U - Crude phthalic anhydride pretreatment systems

Info

Publication number: CN217490771U
Application number: CN202220444302.8U
Authority: CN
Inventors: 李贵艳; 王通; 赵耀
Original assignee: Shandong Hongxin Chemicals Co ltd
Current assignee: Shandong Hongxin Chemicals Co ltd
Priority date: 2022-03-03
Filing date: 2022-03-03
Publication date: 2022-09-27
Anticipated expiration: 2032-03-03

Abstract

The utility model belongs to the technical field of naphthalene method phthalic anhydride production, concretely relates to crude phthalic anhydride pretreatment systems, including crude phthalic anhydride material line, crude phthalic anhydride material line is connected with the preliminary treatment cauldron, the upper portion of preliminary treatment cauldron is through vacuum pipeline and vacuum pump connection, and the preliminary treatment cauldron is connected with the caustic soda liquid jar, is equipped with heating coil on the outer wall of preliminary treatment cauldron, is connected with steam admission valves and lime set water delivery valves on the heating coil, is equipped with the agitator in the preliminary treatment cauldron, and the upper portion of preliminary treatment cauldron is equipped with overflow outlet pipeline. The utility model ensures the pretreatment effect of crude phthalic anhydride by naphthalene method and ensures the product quality by methods of high-temperature heating, heat preservation, liquid caustic soda addition in proportion and the like under the vacuum condition; the steam system can well utilize the characteristic of byproduct steam of the phthalic anhydride device by heating, and the energy is comprehensively utilized by using local materials; meanwhile, the automatic regulating valve group, the explosion-proof port and the nitrogen port are arranged, and the control is scientific, safe and stable.

Description

Crude phthalic anhydride pretreatment system

Technical Field

The utility model belongs to the technical field of naphthalene method phthalic anhydride production, concretely relates to crude phthalic anhydride pretreatment systems of naphthalene method phthalic anhydride device.

Background

Phthalic anhydride is four major organic anhydrides with wide application range, and can be directly used for producing plasticizers, unsaturated polyester resins, alkyd resins and the like. In addition, phthalic anhydride is used in the industrial fields of inks, rubbers, paints, printing, etc., and is also used for the production of pesticides, medicines, etc.

At present, the domestic phthalic anhydride production has an o-benzene route and an industrial naphthalene route. The technological process of the oxidation section of the industrial naphthalene route is that air is pressurized by a blower and preheated by an air heater and then is sent to a vaporizer; liquid naphthalene is pressurized by a pump, vaporized by a naphthalene evaporator and then sent to a vaporizer by a gas naphthalene pipeline; air and naphthalene are uniformly mixed in a vaporizer and then enter a fixed bed reactor filled with a catalyst to react to generate a target product, namely phthalic anhydride and a small part of byproducts. However, the raw material of the naphthalene method phthalic anhydride device is industrial naphthalene, and the purity is low, so that more impurities exist in the crude phthalic anhydride produced by the oxidation reaction.

SUMMERY OF THE UTILITY MODEL

The to-be-solved technical problem of the utility model is: the defect of the prior art is overcome, the crude phthalic anhydride pretreatment system of the naphthalene method phthalic anhydride device is provided, the crude phthalic anhydride can be effectively pretreated, and therefore the next rectification and purification process is facilitated, and the quality of phthalic anhydride products is guaranteed.

The utility model discloses an adopt following technical scheme to realize:

naphthalene method phthalic anhydride device crude phthalic anhydride pretreatment systems, including crude phthalic anhydride material line, crude phthalic anhydride material line is connected with the preliminary treatment cauldron, the upper portion of preliminary treatment cauldron is through vacuum pipeline and vacuum pump connection, the preliminary treatment cauldron is connected with the liquid caustic soda jar, is equipped with heating coil on the outer wall of preliminary treatment cauldron, is connected with steam admission valves and congeals liquid water delivery valves on the heating coil, is equipped with the agitator in the preliminary treatment cauldron, the upper portion of preliminary treatment cauldron is equipped with overflow outlet pipeline.

Preferably, a flow regulating valve group for regulating the feeding amount of the pretreatment kettle according to the flow and a flow meter for displaying the real-time flow are arranged on the crude phthalic anhydride material line.

Preferably, the pretreatment kettle is provided with a liquid level meter, a thermometer, an explosion-proof port for explosion and pressure relief under the condition of overpressure of the pretreatment kettle, a nitrogen port for eliminating abnormal conditions such as vacuum or fire and the like and introducing nitrogen for protection, and a pressure gauge.

Preferably, a caustic soda liquid stirrer is arranged in the caustic soda liquid tank, a caustic soda adding port, a caustic soda liquid level meter and an air release valve are arranged on the caustic soda liquid tank, and the caustic soda liquid tank is connected with the pretreatment kettle through a caustic soda liquid metering pump.

Preferably, the vacuum pump is connected with an inlet valve and a discharge pipeline, the inlet valve can control compressed air entering the vacuum pump to control vacuum pressure, the discharge pipeline can discharge trace organic matters to the waste gas treatment unit, and an air inlet pressure gauge is arranged at the inlet valve.

Preferably, the bottom of the pretreatment kettle is provided with a discharge port, and materials in the kettle can be discharged to other containers through the discharge port when the pretreatment kettle is stopped.

Preferably, the heating coil is connected with a byproduct steam net of the phthalic anhydride device through a steam inlet valve group.

Preferably, be equipped with dispersion impeller and puddler from last to down in proper order on the (mixing) shaft of agitator, the puddler is the setting of X type structure, and surface distribution has the through-hole, can make the more even of material mixture.

Compared with the prior art, the beneficial effects of the utility model are as follows:

1. the utility model discloses under vacuum condition, through methods such as high temperature heating, heat preservation, add liquid caustic soda in proportion, guaranteed the preliminary treatment effect of naphthalene process crude phthalic anhydride, guaranteed product quality.

2. The utility model can utilize the byproduct steam of the phthalic anhydride device by heating in the steam system, and comprehensively utilize energy by using local materials; meanwhile, an automatic regulating valve group, an explosion-proof port and a nitrogen port are arranged, and the control is scientific, safe and stable.

Drawings

Fig. 1 is a schematic structural view of the present invention;

in the figure: 1. a flow regulating valve group; 2. a flow meter; 3. a liquid level meter; 4. a thermometer; 5. an explosion-proof port; 6. a vacuum line; 7. a nitrogen port; 8. a pressure gauge; 9. an overflow outlet conduit; 10. a steam inlet valve bank; 11. a heating coil; 12. a stirrer; 121. a dispersion tray; 122. a stirring rod; 13. a pretreatment kettle; 14. a discharge outlet; 15. a condensate water delivery valve group; 16. a liquid caustic soda metering pump; 17. a liquid caustic soda tank; 18. adding an alkali port; 19. a liquid caustic soda level gauge; 20. a liquid caustic soda agitator; 21. an emptying valve; 22. An inlet valve; 23. a vacuum pump; 24. a discharge line; 25. and an air inlet pressure gauge.

Detailed Description

The present invention will be further described with reference to the accompanying drawings.

As shown in fig. 1, the crude phthalic anhydride pretreatment system of a naphthalene process phthalic anhydride device comprises a crude phthalic anhydride material line, the crude phthalic anhydride material line is connected with a pretreatment kettle 13, a flow regulating valve group 1 and a flow meter 2 are arranged on the crude phthalic anhydride material line, a liquid level meter 3, a thermometer 4, an explosion-proof port 5, a nitrogen port 7 and a pressure gauge 8 are arranged on the pretreatment kettle 13, the upper part of the pretreatment kettle 13 is connected with a vacuum pump 23 through a vacuum pipeline 6, the vacuum pump 23 is connected with an inlet valve 22 and a discharge pipeline 24, an air inlet pressure gauge 25 is arranged at the inlet valve 22, the pretreatment kettle 13 is connected with a liquid caustic soda tank 17 through a liquid caustic soda metering pump 16, a liquid caustic stirrer 20 is arranged in the liquid caustic tank 17, an alkali adding port 18, a liquid caustic soda liquid level meter 19 and an air release valve 21 are arranged on the liquid caustic tank 17, a heating coil 11 is arranged on the outer wall of the pretreatment kettle 13, a steam inlet valve group 10 and a condensate water delivery valve group 15 are connected on the heating coil 11, heating coil 11 is connected with phthalic anhydride device byproduct steam net through steam admission valves 10, is equipped with agitator 12 in the preliminary treatment cauldron 13, is equipped with two-sided tooth dispersion impeller 121 and puddler 122 from last to down in proper order on the (mixing) shaft of agitator 12, and puddler 122 is the setting of X type structure, and surface distribution has the through-hole, and the upper portion of preliminary treatment cauldron 13 is equipped with overflow outlet pipeline 9, and the bottom of preliminary treatment cauldron 13 is equipped with bin outlet 14.

When the pretreatment kettle works, firstly, vacuum is started, an inlet valve 22 of a vacuum pump 23 is opened, compressed air entering the vacuum pump 23 is controlled according to pressure display of an air inlet pressure gauge 23, the vacuum pump 23 is started, and micro negative pressure is formed in the pretreatment kettle 13 through a vacuum pipeline 6 under the action of the vacuum pump 23. The crude phthalic anhydride from the pre-unit by naphthalene method is regulated by a crude phthalic anhydride flow regulating valve group 1 according to the material flow displayed by a crude phthalic anhydride flow meter 2, and the material quantity of the crude phthalic anhydride entering a pretreatment kettle 13 is regulated. Simultaneously, starting a liquid caustic soda metering pump 16 to inject liquid caustic soda into the pretreatment kettle 13 according to the material quantity in proportion, starting a liquid caustic soda tank stirrer 20 to ensure that the liquid caustic soda solution is fully and uniformly mixed, supplementing the liquid caustic soda into the liquid caustic soda tank 17 through an alkali adding port 18 according to a liquid caustic soda liquid level meter 19, and discharging the liquid caustic soda tank 17 through an emptying valve 21 when the liquid caustic soda tank 17 needs to be emptied. The vacuum degree of the vacuum pump 23 is adjusted, so that the pressure gauge 8 of the pretreatment kettle 13 displays vacuum to meet the process requirements, and the vacuum stability of the pretreatment kettle is ensured. According to the liquid level display of the liquid level meter 3 of the pretreatment kettle 13, when the crude phthalic anhydride of the pretreatment kettle reaches a certain liquid level, the stirrer 12 is started to stir, so that the crude phthalic anhydride materials are uniformly mixed. The steam inlet valve group 10 is opened, steam enters the steam heating coil pipe 11, crude phthalic anhydride in the pretreatment kettle 13 is heated, the temperature is controlled by adjusting the opening degree of the steam inlet valve group 10 according to the display of the single thermometer 4 of the pretreatment kettle 13, and steam condensate is discharged to a steam condensate pipe network through the condensate water delivery valve group 15. The crude phthalic anhydride entering the pretreatment kettle 13 is heated, and partial by-products are decomposed into micromolecular materials under the action of high temperature, and the micromolecular materials are taken away through the vacuum pipeline 6 and finally the vacuum discharge pipeline 24 and discharged to the waste gas treatment unit. The liquid caustic soda continuously enters the pretreatment kettle 13 according to a certain proportion to neutralize the mixed acid in the material into macromolecular salts, and the pretreatment effect is achieved by the method.

The material gets into preliminary treatment cauldron 13 in succession, when reaching the overflow height, the material that gets into preliminary treatment cauldron 13 at first gets into next unit through overflow outlet pipeline 9, and the setting of overflow outlet pipeline 9 has guaranteed the dwell time of crude phthalic anhydride material in the cauldron, can reach the preliminary treatment effect, and the processing procedure is continuous production. When the pretreatment kettle 13 is stopped, the materials in the kettle are discharged to other containers through a discharge port 14. The pretreatment kettle 13 is provided with an explosion-proof port 5, if the equipment is safe due to explosion and pressure relief under the condition of overpressure, and a nitrogen port 7 is arranged for eliminating abnormal conditions such as vacuum or ignition and introducing nitrogen for protection, so that the operation safety is ensured.

Of course, the above description is only a preferred embodiment of the present invention, and should not be taken as limiting the scope of the embodiments of the present invention. The present invention is not limited to the above examples, and the equivalent changes and improvements made within the essential scope of the present invention should be included within the patent coverage of the present invention.

Claims

1. A crude phthalic anhydride pretreatment system, includes crude phthalic anhydride material line, its characterized in that: the crude phthalic anhydride material line is connected with a pretreatment kettle (13), the upper part of the pretreatment kettle (13) is connected with a vacuum pump (23) through a vacuum pipeline (6), the pretreatment kettle (13) is connected with a liquid caustic soda tank (17), a heating coil (11) is arranged on the outer wall of the pretreatment kettle (13), a steam inlet valve bank (10) and a condensate water delivery valve bank (15) are connected onto the heating coil (11), a stirrer (12) is arranged in the pretreatment kettle (13), and an overflow outlet pipeline (9) is arranged on the upper part of the pretreatment kettle (13).

2. The crude phthalic anhydride pretreatment system of claim 1, wherein: the crude phthalic anhydride material line is provided with a flow regulating valve group (1) and a flowmeter (2).

3. The crude phthalic anhydride pretreatment system of claim 1, wherein: the pretreatment kettle (13) is provided with a liquid level meter (3), a thermometer (4), an explosion-proof port (5), a nitrogen port (7) and a pressure gauge (8).

4. The crude phthalic anhydride pretreatment system of claim 1, wherein: a liquid caustic soda stirrer (20) is arranged in the liquid caustic soda tank (17), an alkali adding port (18), a liquid caustic soda liquid level meter (19) and an air release valve (21) are arranged on the liquid caustic soda tank (17), and the liquid caustic soda tank (17) is connected with the pretreatment kettle (13) through a liquid caustic soda metering pump (16).

5. The crude phthalic anhydride pretreatment system of claim 1, wherein: an inlet valve (22) and a discharge pipeline (24) are connected to the vacuum pump (23), and an air inlet pressure gauge (25) is arranged at the inlet valve (22).

6. The crude phthalic anhydride pretreatment system of claim 1, wherein: the bottom of the pretreatment kettle (13) is provided with a discharge outlet (14).

7. The crude phthalic anhydride pretreatment system of claim 1, wherein: the heating coil pipe (11) is connected with a byproduct steam net of the phthalic anhydride device through a steam inlet valve group (10).

8. The crude phthalic anhydride pretreatment system of claim 1, wherein: a dispersion disc (121) and a stirring rod (122) are sequentially arranged on a stirring shaft of the stirrer (12) from top to bottom.

9. The crude phthalic anhydride pretreatment system of claim 8, wherein: the stirring rod (122) is arranged in an X-shaped structure, and through holes are distributed on the surface of the stirring rod.