Spraying device in process of preparing phthalic anhydride by naphthalene method
By designing a spray device including a spiral nozzle and a heat tracing tube, the problem of the inability to effectively remove impurities inside the switching condenser in the prior art is solved, and more efficient condensation and more stable phthalic anhydride yield are achieved.
Patent Information
- Application Number
- CN202422024028.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-20
- Publication Date
- 2025-06-27
- Estimated Expiration
- 2034-08-20
AI Technical Summary
The spraying device during the existing naphthalene method of phthalanhydride production cannot effectively remove impurities condensed at the dead corners of the switching condenser, fins, etc., resulting in a reduction in condensation efficiency, a shortened safe operation cycle and an impact on phthalanhydride production.
A spray device including switching condenser, U-shaped condenser, spray pipe and spiral nozzle is designed. The spray liquid is uniformly sprayed in multiple corners of the U-shaped condenser and switched condenser side wall through the spiral nozzle, and the heat tracing tube is used to reduce the crystallization of crude phthalanhydride to ensure the smooth flow of the spray liquid.
Effectively remove impurities in the internal blind corners of the condenser and fins, improve condensation efficiency and safe operation cycle, ensure the stability of phthalic anhydride production, and reduce raw material consumption.
Smart Images
Figure CN223027619U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of chemical production equipment, and particularly relates to a spraying device in the process of producing phthalic anhydride by the naphthalene method. Background Art
[0002] In the process of producing phthalic anhydride by the naphthalene method, industrial naphthalene is heated in a naphthalene evaporator, and the generated naphthalene vapor enters a naphthalene-air mixer after being metered. The air coming out of the blower is metered and first enters a two-stage air preheater for heating, and then enters the naphthalene-air mixer. After being fully and evenly mixed with the naphthalene vapor from the naphthalene vaporizer, it enters the reactor. Under the action of a catalyst, an oxidation reaction occurs to obtain the required product phthalic anhydride and by-products naphthoquinone and maleic anhydride. The reacted gas leaves the reactor and is cooled in a gas cooler. The cooled reaction product gas enters a switching condenser to achieve the purpose of retaining crude phthalic anhydride and separating excess air and light components. In the actual operation process, impurities such as phthalic anhydride and polymers are likely to condense at the internal dead corners, container walls, and fin tube gaps of the switching condenser, which will cause blockage, reduce the condensation efficiency of the switching condenser, shorten the safe operation period of the switching condenser, and also affect the output of phthalic anhydride. The iron salts of some side reaction products may spontaneously combust above 160°C, causing accidents.
[0003] In the prior art, there are also devices that use spraying to remove impurities on the switching condenser. However, first, because the spraying liquid is generally selected as crude phthalic anhydride, crude phthalic anhydride is prone to crystallization at low temperatures and is likely to cause blockage of the spray pipe. Second, the existing spraying devices are generally arranged on the upper part of the switching condenser. Due to the selection of the spray head, the spraying angle is fixed, and the lower part of the container dead corners and fins cannot be cleaned during spraying. Therefore, the spraying is not thorough and the accumulation of impurities cannot be completely eliminated. The above problems have always troubled the actual production. Summary of the Invention
[0004] The technical problem to be solved by the utility model is to provide a spraying device in the process of producing phthalic anhydride by the naphthalene method, which overcomes the defects of the prior art, can ensure the conveying efficiency of the spray pipe, effectively remove the impurities condensed at the internal dead corners, fins, etc. of the switching condenser, and ensure the spraying effect.
[0005] To solve the above technical problem, the technical solution of the utility model is:
[0006] A spraying device in the process of producing phthalic anhydride by the naphthalene method, comprising a switching condenser. A number of rows of U-shaped condenser tubes are arranged in the switching condenser, and a number of fins are evenly arranged on the U-shaped condenser tubes. A crude phthalic anhydride outlet is arranged at the bottom of the switching condenser, and an air inlet is arranged at the bottom of one side wall of the switching condenser. A spraying pipe is arranged at the upper part of the switching condenser, and a heat tracing pipe is arranged outside the spraying pipe. The lower part of the spraying pipe is connected with spraying branch pipes, and a number of spiral nozzles are evenly arranged between each U-shaped condenser tube and between the U-shaped condenser tube and the side wall of the switching condenser.
[0007] Preferably, the crude phthalic anhydride outlet is connected to a crude phthalic anhydride storage tank through a pipeline. The crude phthalic anhydride is collected and then transported to the subsequent process for further processing.
[0008] Preferably, the air inlet is connected to a gas cooler in the previous process through a pipeline and a valve.
[0009] Preferably, the heat transfer medium in the U-shaped condenser tube is heat-conducting oil; the heat transfer medium in the heat tracing pipe is steam.
[0010] Preferably, the spraying pipe is connected to a crude phthalic anhydride storage tank through a high-pressure pump. High-pressure crude phthalic anhydride is supplied for spraying.
[0011] Preferably, the number of the spraying branch pipes is one row more than the number of rows of the U-shaped condenser tubes. They are respectively arranged between each U-shaped condenser tube and between the U-shaped condenser tube and the side wall of the switching condenser.
[0012] Preferably, eight spiral nozzles are arranged in each row and are evenly arranged on the spraying branch pipes.
[0013] Preferably, the spiral nozzles are DN8 spiral nozzles.
[0014] Due to the adoption of the above technical solutions, the beneficial effects of the present utility model are as follows:
[0015] The spraying liquid of the present utility model utilizes the crude phthalic anhydride generated in the production process. After spraying, it is continuously processed together with the crude phthalic anhydride obtained by gas cooling, without the need to additionally increase materials, reducing raw material consumption; the spraying pipe is provided with a jacket, and heat tracing is used to reduce the crystallization of crude phthalic anhydride, effectively ensuring the smoothness of the spraying liquid conveying pipeline, thereby ensuring the spraying effect; by using spraying branch pipes and their spiral nozzles arranged at different positions, the effects of a large spraying plane, uniform flow rate, and adjustable spraying direction can be achieved, effectively removing impurities at each position.
[0016] In short, the present utility model can ensure the conveying efficiency of the spraying pipe, effectively remove impurities condensed at dead corners, fins, etc. inside the switching condenser, and ensure the spraying effect. Brief Description of the Drawings
[0017] Figure 1 It is a schematic structural diagram of an embodiment of the present utility model;
[0018] In the figure, 1 is a switching condenser; 2 is a U-shaped condenser tube; 3 are fins; 4 is a spray pipe; 5 is a tracing pipe; 6 are spray branch pipes; 7 are spiral nozzles. Specific embodiments
[0019] The present utility model will be further described below in conjunction with the accompanying drawings and embodiments.
[0020] Embodiment 1:
[0021] As Figure 1 shown, a spray device in the process of producing phthalic anhydride by the naphthalene method includes a switching condenser 1. A number of rows of U-shaped condenser tubes 2 are provided in the switching condenser 1, and a number of fins 3 are evenly provided on the U-shaped condenser tubes 2; a crude phthalic anhydride outlet (not marked) is provided at the bottom of the switching condenser 1, and an air inlet (not marked) is provided at the bottom of one side wall of the switching condenser 1; a spray pipe 4 is provided at the upper part of the switching condenser 1, and a tracing pipe 5 is provided outside the spray pipe 4; a spray branch pipe 6 is connected to the lower part of the spray pipe 4, and a number of spiral nozzles 7 are evenly provided between each U-shaped condenser tube 2 and between the U-shaped condenser tube 2 and the side wall of the switching condenser 1.
[0022] During actual production, when phthalic anhydride gas at about 170 °C obtained in the current process enters the switching condenser 1 for cooling, heat-conducting oil at about 55 - 57 °C is introduced into the U-shaped condenser tubes 2 in the switching condenser 1 to exchange heat with the phthalic anhydride gas; at the same time, a high-pressure pump (not marked) connected to the spray pipe 4 is turned on to pump crude phthalic anhydride in a crude phthalic anhydride storage tank (not marked) into the spray pipe 4, and the spiral nozzles 7 are used to spray various corners in the switching condenser 1, the fins 3 on the U-shaped condenser tubes 2, etc., to avoid the accumulation of impurities in the above areas; a steam heat exchange medium is introduced into the tracing pipe of the spray pipe to heat the crude phthalic anhydride in the spray pipe 4 to prevent the crude phthalic anhydride from cooling and crystallizing, resulting in pipeline blockage; the phthalic anhydride gas is cooled and condensed into crude phthalic anhydride, which is collected together with the crude phthalic anhydride used for spraying into the crude phthalic anhydride storage tank, and after the cooling is completed, it is transported to the subsequent process for further processing together. Through the above operations, the accumulation of impurities on the fin surface of the switching condenser is avoided, its heat exchange effect is ensured, and the loss of phthalic anhydride production is prevented.
[0023] It should be understood that these embodiments are only used to illustrate the present utility model and not to limit the scope of the present utility model. In addition, it should be understood that after reading the content taught by the present utility model, those skilled in the art can make various changes or modifications to the present utility model, and these equivalent forms also fall within the scope defined by the appended claims of this application.
Claims
1. A spraying device in a naphthalene-based phthalic anhydride process, characterized in that: It comprises a switching condenser, wherein a plurality of rows of U-shaped condensing tubes are arranged inside the switching condenser, and a plurality of fins are evenly arranged on the U-shaped condensing tubes; a crude phthalic anhydride outlet is arranged at the bottom of the switching condenser, and an air inlet is arranged at the bottom of a side wall of the switching condenser; a spray pipe is arranged at the top of the switching condenser, and a heating pipe is arranged outside the spray pipe; a spray branch pipe is connected to the bottom of the spray pipe, and a plurality of spiral nozzles are evenly arranged on the spray branch pipe between each U-shaped condensing tube and between the U-shaped condensing tube and the side wall of the switching condenser.
2. The spraying device in the naphthalene-based phthalic anhydride process as claimed in claim 1, wherein: The crude phthalic anhydride outlet is connected to the crude phthalic anhydride storage tank through a pipeline.
3. The spraying device in the naphthalene-based phthalic anhydride process as claimed in claim 1 is characterized in that: The air inlet is connected to the gas cooler of the previous process through a pipeline and a valve.
4. The spraying device in the naphthalene-based phthalic anhydride process as claimed in claim 1 is characterized in that: The spray pipe is connected to the crude phthalic anhydride storage tank through a high-pressure pump.
5. The spraying device in the naphthalene-based phthalic anhydride process as claimed in claim 1 is characterized in that: The number of the spray branch pipes is one more than the number of rows of the U-shaped condensing pipes.
6. The spraying device in the naphthalene-based phthalic anhydride process as claimed in claim 1, wherein: The spiral nozzles are arranged in eight rows in each row and are evenly arranged on the spray branch pipes.
7. The spraying device in the naphthalene-based phthalic anhydride process as claimed in claim 1, wherein: The spiral nozzle is a DN8 spiral nozzle.