Two-stage continuous desolventizing device for desolventizing omethoate

Abstract

The utility model discloses a two-stage continuous desolventizing device for desolventizing omethoate. The two-stage continuous desolventizing device comprises a first-stage film evaporator, a second-stage film evaporator, a first-stage receiving tank and a finished product receiving tank, a feeding pipe and a first-stage solvent discharging pipe are arranged at the upper end part of the first-stage film evaporator, the bottom of the first-stage film evaporator is connected with an inlet of the first-stage receiving tank through a first-stage pipeline, an outlet of the first-stage receiving tank is connected with an inlet of the second-stage film evaporator through a second-stage pipeline, and a second-stage solvent discharging pipe is arranged at the upper part of the second-stage film evaporator; an outlet of the secondary film evaporator is connected to a finished product receiving tank through a finished product pipeline; according to the utility model, the two stages of film evaporators connected in series are used for desolventizing materials, continuous desolventizing is carried out in a quick-feeding and quick-discharging manner of the materials, and the secondary film evaporator is used for evaporating and desolventizing in a vacuum manner, so that the desolventizing effect is improved stage by stage, residual materials in the equipment can be reduced, and the production cost is reduced. And the desolventizing efficiency of the material is effectively improved (1500L of methyl chloroacetate can be evaporated in 2.5 hours), the number of desolventizing post personnel can be reduced, and the production safety is improved.

Description

Technical Field

[0001] The utility model relates to the field of chemical production equipment, in particular to a two-stage continuous desolventizing device for desolventizing omethoate. Background Art

[0002] Post-aminolysis is a commonly used method for preparing omethoate. The method is to heat p-toluene diphenol and phosphorus oxychloride in an appropriate solvent for reaction. The reaction temperature is usually between 80°C and 120°C. Under this reaction condition, phosphorus oxychloride is formylated to form the precursor compound of omethoate. After the formylation reaction, the product needs to be hydrolyzed. Hydrolysis is to add the generated ester compound to an alkaline solution to hydrolyze it into the corresponding acid and alcohol. In this step, an alkaline solution (such as sodium hydroxide) is usually used for the hydrolysis reaction. After hydrolysis, the obtained solution needs to be extracted and purified to separate the target product. Organic solvents (such as methanol, ether, etc.) are usually used for extraction, and purification is carried out by crystallization, filtration and other methods. Finally, the prepared omethoate crude oil is first dried and then desolventized to obtain omethoate crude oil.

[0003] At present, the desolventizing process in the production of oxydemeton-methyl is usually carried out by removing solvents such as chloroacetic acid and methyl ester through a reactor. The desolventizing process requires on-site personnel to observe at all times to control the temperature (safety accidents are prone to occur when the temperature exceeds 150°C), and the material desolventizing time is too long to easily lead to decomposition, which places high requirements on the operators. In the actual production process, it takes 2.5 hours to evaporate 1000L of methyl chloroacetate. The desolventizing efficiency is low and needs to be improved. Utility Model Content

[0004] In order to solve the above problems, the utility model provides a two-stage continuous desolventizing device for desolventizing omethoate.

[0005] The technical scheme of the utility model is: a two-stage continuous desolventizing device for oxydemeton-methyl desolventizing, comprising a primary thin film evaporator, a secondary thin film evaporator, a primary receiving tank and a finished product receiving tank, the primary thin film evaporator and the secondary thin film evaporator having the same size; a feed pipe and a primary solvent discharge pipe are arranged symmetrically at the upper end of the primary thin film evaporator, the feed pipe and the primary solvent discharge pipe are symmetrically arranged, the bottom is connected with the inlet of the primary receiving tank through a primary pipeline, the outlet of the primary receiving tank is connected with the inlet of the secondary thin film evaporator through a secondary pipeline, a secondary solvent discharge pipe is arranged at the upper part of the secondary thin film evaporator, the outlet of the secondary thin film evaporator is connected to the finished product receiving tank through a finished product pipeline, and the upper ends of the two thin film evaporators are driven by installing a reduction motor; a centrifugal pump A is installed on the primary pipeline, a centrifugal pump B is installed on the secondary pipeline, and a centrifugal pump C is installed on the finished product pipeline.

[0006] Preferably, the outer end of the primary solvent discharge pipe is connected to a plurality of primary condensers in parallel via a condensation pipe, the primary condensers are connected to each other in parallel, and a primary drain pipe is provided on the terminal primary condenser.

[0007] Preferably, the outlets of the various primary condensers are connected to a primary solvent recovery tank via condensation pipes, and the primary solvent recovery tank adopts a vertical tank structure.

[0008] Preferably, the outer end of the secondary solvent discharge pipe is connected to a plurality of secondary condensers in parallel via a condensation pipe, the secondary condensers are connected to each other in parallel, and the second-level condenser at the end is provided with a secondary drain pipe.

[0009] Preferably, the outlets of the respective secondary condensers are connected to a secondary solvent recovery tank via a condensation pipe, and the secondary solvent recovery tank also adopts a vertical tank structure.

[0010] Preferably, a vacuum pump is installed on the secondary exhaust pipe.

[0011] Preferably, a flow retarder is installed on both the primary pipeline and the secondary pipeline, and a transparent window is provided on the side wall of the chamber of the flow retarder, and the transparent window is made of high-strength glass fixedly connected by a flange.

[0012] Preferably, the primary thin film evaporator and the secondary thin film evaporator are both scraped thin film evaporators.

[0013] Preferably, the upper part of the scraper film evaporator is provided with a blade distributor fixedly mounted on the scraper shaft, the center of the blade distributor is the shaft sleeve, the blade distributor includes a plurality of inclined distribution plates evenly arranged along the circumference, and the outer end of the inclined distribution plate is close to the inner wall of the evaporator.

[0014] The beneficial technical effects of the utility model are:

[0015] (1) The utility model adopts a two-stage series-connected thin film evaporator to desolventize the material. The thin film evaporator can be set to a fixed temperature and continuously desolventize the material in a fast-in-fast-out manner. The second-stage thin film evaporator uses a vacuum method to evaporate and desolventize, which gradually improves the desolventizing effect and can reduce the residual material in the equipment. The desolventizing efficiency of the material is effectively improved (1500L of methyl chloroacetate can be evaporated in 2.5 hours), and the number of personnel in the desolventizing position can be reduced, thereby improving the safety of production.

[0016] (2) The utility model optimizes the distribution structure of the thin film evaporator and adopts a blade-type distributor that rotates synchronously with the scraper shaft. After the material enters the surface of the distributor, it will be evenly dispersed by each distribution plate and thrown onto the inner wall of the evaporator due to centrifugal force, thereby improving the uniformity of thin film formation and further improving the evaporation and desolventization efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a system diagram of the utility model;

[0018] Figure 2 It is a structural schematic diagram of a primary thin film evaporator or a secondary thin film evaporator of the utility model;

[0019] Figure 3 yes Figure 2 AA section view of the structure.

[0020] In the figure, 11. primary thin film evaporator, 111. primary receiving tank, 112. feed pipe, 113. primary pipeline, 114. primary solvent discharge pipe, 12. secondary thin film evaporator, 121. finished product receiving tank, 122. secondary pipeline, 123. secondary solvent discharge pipe, 13. finished product pipeline, 141. centrifugal pump A, 142. centrifugal pump B, 143. centrifugal pump C, 161. primary condenser, 162. primary exhaust pipe, 163. primary solvent recovery tank, 171. secondary exhaust pipe, 172. secondary condenser, 173. secondary solvent recovery tank, 174. vacuum pump, 18. retarder, 181. transparent window, 19. scraper shaft, 20. blade distributor, 201. inclined distribution plate, 202. inner wall of evaporator. DETAILED DESCRIPTION

[0021] Example 1, see the attached specification Figure 1 A two-stage continuous desolventizing device for oxydemeton-methyl desolventizing comprises a primary thin film evaporator 11, a secondary thin film evaporator 12, a primary receiving tank 111 and a finished product receiving tank 121; the upper end of the primary thin film evaporator 11 is provided with a feed pipe 112 and a primary solvent discharge pipe 114, and the bottom is connected to the inlet of the primary receiving tank 111 through a primary pipeline 113, the primary thin film evaporator 11 delivers the crude oil after desolventizing from the primary pipeline 113 to the primary receiving tank 111, and the outlet of the primary receiving tank 111 is connected to the inlet of the secondary thin film evaporator 12 through a secondary pipeline 122. Then, a secondary solvent discharge pipe 123 is provided at the upper part of the secondary thin film evaporator 12, and the outlet of the secondary thin film evaporator 12 is connected to the finished product receiving tank 121 through the finished product pipeline 13. The secondary thin film evaporator 12 delivers the crude oil after the second desolventization from the secondary pipeline 122 to the finished product receiving tank 121; a centrifugal pump A 141 is installed on the primary pipeline 113, a centrifugal pump B 142 is installed on the secondary pipeline 122, and a centrifugal pump C 143 is installed on the finished product pipeline 13. The centrifugal pump is used to increase the flow speed of the material in the pipeline, thereby improving the efficiency of continuous and uninterrupted desolventization.

[0022] The outer end of the primary solvent discharge pipe 114 is connected to multiple primary condensers 161 in parallel through a condensation pipe, and the last primary condenser 161 is provided with a primary drain pipe 162. The outlets of each primary condenser 161 are connected to a primary solvent recovery tank 163 through a condensation pipe. The solvents extracted from the primary desolvation are condensed and recovered through these parallel primary condensers 161, and the solvents are stored in the recovery tank for reuse.

[0023] The outer end of the secondary solvent discharge pipe 123 is connected to multiple secondary condensers 172 in parallel through a condensation pipe. The last secondary condenser 172 is provided with a secondary drain pipe 171. The outlets of each secondary condenser 172 are connected to a secondary solvent recovery tank 173 through a condensation pipe. A vacuum pump 174 is installed on the secondary drain pipe 171. The vacuum pump 174 evacuates the secondary thin film evaporator 12 through the secondary condenser 172, and condenses and recovers the solvents extracted from the secondary desolvation through these parallel secondary condensers 172, and stores these solvents in a recovery tank for reuse.

[0024] The first-level pipeline 113 and the second-level pipeline 122 are both installed with a flow retarder 18, and a transparent window 181 is provided on the side wall of the chamber of the flow retarder 18. After the material enters the circulator, its color, flow state and other characteristics can be observed from the transparent window 181, which is conducive to real-time grasp of the desolvation state of the material.

[0025] The working process and principle of this embodiment are as follows: the material enters the primary thin film evaporator 11 from the feed pipe 112, enters the primary receiving tank 111 from the primary pipeline 113 after the primary desolventizing, and enters the secondary thin film evaporator 12 from the primary receiving tank 111, and after the secondary desolventizing, the finished crude oil is formed and enters the finished product receiving tank 121. During this process, the primary condenser 161 condenses and recovers the solvent desolventized by the primary thin film evaporator 11, and stores the solvent in the recovery tank for reuse. The secondary condenser 172 condenses and recovers the solvent desolventized again, and stores the solvent in the recovery tank for reuse. At the same time, the vacuum pump 174 evacuates the secondary thin film evaporator 12 through the condenser and the pipeline, thereby improving the desolventizing effect step by step, reducing the residual material in the equipment, effectively improving the desolventizing efficiency of the material, and reducing the number of personnel in the desolventizing position.

[0026] Example 2, see the attached specification Figure 2-3 The primary thin film evaporator 11 and the secondary thin film evaporator 12 in the first embodiment are both scraper thin film evaporators. The upper part of the scraper thin film evaporator is provided with a blade distributor 20 fixedly mounted on the scraper shaft 19. The blade distributor 20 includes a plurality of inclined distribution plates 201 evenly arranged along the circumference. The distribution plates are staggered with each other, and the outer ends of the distribution plates are arc structures. The outer ends of the inclined distribution plates 201 are close to the inner wall 202 of the evaporator.

[0027] When the scraper shaft 19 of this embodiment rotates, the blade distributor 20 can rotate synchronously with the scraper shaft 19. After the material enters the surface of the distributor from the feed pipe 112, it will be evenly dispersed by each distribution plate due to centrifugal force and thrown onto the inner wall 202 of the evaporator, thereby improving the uniformity of film formation and further improving the evaporation and desolventization efficiency.

Claims

1. A two-stage continuous desolventizing device for omethoate desolventizing, characterized in that: It comprises a primary thin film evaporator, a secondary thin film evaporator, a primary receiving tank and a finished product receiving tank; a feed pipe and a primary solvent discharge pipe are arranged at the upper end of the primary thin film evaporator, the bottom is connected with the inlet of the primary receiving tank through a primary pipeline, the outlet of the primary receiving tank is connected with the inlet of the secondary thin film evaporator through a secondary pipeline, a secondary solvent discharge pipe is arranged at the upper part of the secondary thin film evaporator, and the outlet of the secondary thin film evaporator is connected to the finished product receiving tank through a finished product pipeline; a centrifugal pump A is installed on the primary pipeline, a centrifugal pump B is installed on the secondary pipeline, and a centrifugal pump C is installed on the finished product pipeline.

2. A two-stage continuous desolventizing device for omethoate desolventizing according to claim 1, characterized in that: The outer end of the primary solvent discharge pipe is connected to a plurality of primary condensers in parallel through a condensation pipeline, and a primary exhaust pipe is arranged on the first-stage condenser at the end.

3. A two-stage continuous desolventizing device for omethoate desolventizing according to claim 2, characterized in that: The outlets of the various primary condensers are connected to the primary solvent recovery tank via condensation pipes.

4. A two-stage continuous desolventizing device for omethoate desolventizing according to claim 1, characterized in that: The outer end of the secondary solvent discharge pipe is connected to a plurality of secondary condensers in parallel through a condensation pipeline, and a secondary drain pipe is arranged on the second condenser at the end.

5. A two-stage continuous desolventizing device for omethoate desolventizing according to claim 4, characterized in that: The outlets of the secondary condensers are connected to the secondary solvent recovery tank via condensation pipelines.

6. A two-stage continuous desolventizing device for desolventizing omethoate according to claim 5, characterized in that: A vacuum pump is installed on the secondary exhaust pipe.

7. A two-stage continuous desolventizing device for desolventizing omethoate according to claim 1, characterized in that: A flow retarder is installed on both the primary pipeline and the secondary pipeline, and a transparent window is arranged on the side wall of the chamber of the flow retarder.

8. A two-stage continuous desolventizing device for desolventizing omethoate according to claim 1, characterized in that: The primary thin film evaporator and the secondary thin film evaporator are both scraped thin film evaporators.

9. A two-stage continuous desolventizing device for desolventizing omethoate according to claim 8, characterized in that: The upper part of the scraper film evaporator is provided with a blade distributor fixedly sleeved on the scraper shaft. The blade distributor includes a plurality of inclined distribution plates evenly arranged along the circumference, and the outer ends of the inclined distribution plates are close to the inner wall of the evaporator.

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