Continuous distillation device

Abstract

The invention belongs to the technical field of organic chemical engineering, and particularly relates to a continuous distillation device. The whole device is cylindrical, the interior of the device is of an interlayer structure, namely, an outer cylinder and an inner cylinder are nested, an interlayer channel is formed between the outer cylinder and the inner cylinder, a stirring paddle is arranged in the middle of the interior of the inner cylinder, and the outer side of a paddle blade of the stirring paddle clings to the inner wall of the inner cylinder; a feed port and two discharge ports are formed in the inner cylinder, and an inlet and an outlet are formed in the interlayer channel; a to-be-distilled solution flows in the inner cylinder, and a water bath or an oil bath can pass through the interlayer channel to control the distillation temperature of the inner cylinder; the continuous distillation device realizes continuous distillation of a to-be-distilled solution through the inlet and the outlet of the inner cylinder, and temperature adjustment is performed on continuous distillation of the distilled solution in the inner cylinder through interlayer channel water bath or oil bath. The device can be used for continuously and efficiently separating mixtures with different boiling points, and is suitable for compounds which are unstable after being heated for a long time.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of organic chemical engineering, and particularly relates to a continuous distillation device. BACKGROUND

[0002] The medical, pesticide and chemical industries often have separation of solvents and products or separation of compounds with different boiling points. The traditional method is to use a kettle type batch distillation, which has high energy consumption, low efficiency and is prone to decomposition of heat-sensitive compounds. The method of the present application can continuously and efficiently separate mixtures with different boiling points, and is suitable for separation of heat-sensitive compounds, and is particularly suitable for continuous flow manufacturing. SUMMARY

[0003] In order to overcome the defects of traditional distillation, the present application provides a continuous distillation device, which can realize continuous and efficient separation and is easy to be applied in industry.

[0004] The continuous distillation device provided by the present application is also called a continuous distillation kettle. The overall device is in the shape of a cylinder, and the inside is a sandwich structure, that is, the outer cylinder 6 and the inner cylinder 7 are nested, and the sandwich channel 8 is between the outer cylinder 6 and the inner cylinder 7. The inner cylinder is provided with a stirring paddle 9 in the middle, and the outer side of the stirring paddle blade is tightly attached to the inner wall of the inner cylinder. The inner cylinder is provided with a feed inlet 1 corresponding to the top position of the stirring paddle, a low-boiling-point compound discharge outlet 2 corresponding to the position above the top of the stirring paddle, and a high-boiling-point compound discharge outlet 3 at the bottom of the inner cylinder. The jacket inlet 4 is provided at the side of the bottom of the sandwich channel 8, and the jacket outlet 5 is provided at the side of the upper part of the sandwich channel.

[0005] The stirring paddle is driven by a motor and the rotating speed is controlled. Within a certain rotating speed range, as the rotating speed increases, the liquid is scraped off along the inner wall of the inner cylinder 7 through the outer side of the stirring paddle blade to form a liquid film, so as to improve the specific surface area of the liquid under heating, thereby improving the distillation efficiency. The preferred rotating speed is 200-600 rpm / min.

[0006] The inner cylinder is used for flowing of the solution to be distilled, and the sandwich channel can be connected to a water bath or an oil bath to control the distillation temperature of the inner cylinder.

[0007] The device is connected to a condenser and a low-boiling-point solvent collection tank outside the discharge outlet 2. The inlet of the condenser is connected to the discharge outlet 2 of the device, the outlet of the condenser is connected to the collection tank, and a vacuum degree control valve is connected above the collection tank.

[0008] The vacuum degree of the system of the device is controlled by the vacuum degree valve on the collection tank, and the preferred vacuum degree is 20-1000 mbar.

[0009] The material of the device is glass, polytetrafluoroethylene or stainless steel.

[0010] The inner diameter of the inner cylinder 7 is 3-100 cm, and the width of the interlayer channel 8 is 2-10 cm; preferably, the inner diameter of the inner cylinder 7 is 5-80 cm, and the width of the interlayer channel 8 is 2-6 cm.

[0011] The continuous distillation vessel designed in this invention performs the following continuous distillation process: After the solution to be distilled is continuously fed into the vessel through the feed inlet 1 by the feed pump, the liquid to be distilled is stirred at a certain speed by the agitator 9 to form a liquid film along the inner wall of the inner cylinder 7, thereby increasing the heat-receiving specific surface area of ​​the solution to be distilled; the jacket channel 8 is fed with pre-temperature controlled water or heat transfer oil through the inlet 4 to control a certain distillation temperature, and flows out from the jacket channel outlet 5; under normal or reduced pressure conditions, low-boiling-point compounds are continuously distilled out from the outlet 2, and high-boiling-point compounds are continuously flowed out from the outlet 3 by the feed pump. Attached Figure Description

[0012] Figure 1 This is a structural diagram of the continuous distillation apparatus of the present invention.

[0013] The labels in the diagram are as follows: 1 is the inlet of the reactor body, 2 is the outlet of low-boiling-point compounds, 3 is the outlet of high-boiling-point compounds, 4 is the jacket inlet, 5 is the jacket outlet; 6 is the outer cylinder, 7 is the inner cylinder, 8 is the jacketed channel, and 9 is the stirring paddle. Detailed Implementation

[0014] The present invention will be further described below through examples.

[0015] The structure of the reaction system used in the examples is shown in the attached figure. Figure 1 As shown, its structure includes a vessel inlet 1, vessel outlets 2 and 3, jacket inlet and outlet 4 and 5, and a stirring paddle attached to the inner wall of the vessel. After the distillation solution enters the vessel, it is dispersed by the stirring paddle and forms a thin film. Under normal or reduced pressure conditions, low-boiling-point compounds are continuously distilled out from outlet 2, and high-boiling-point compounds are continuously discharged from outlet 3.

[0016] Example 1: Separation of a mixed solution of dichloromethane and toluene; The vacuum level of the device is controlled to 200 mbar by the vacuum control valve above the collection tank. Water with a pre-controlled external temperature flows in through the jacket inlet 4 and flows out through the jacket outlet 5, keeping the temperature of the jacket 8 at 30 ℃. The stirring paddle speed is 300 rpm / min. A toluene solution containing 30% dichloromethane is continuously pumped to the feed inlet 1 at a flow rate of 5 ml / min. Dichloromethane is continuously distilled out from the outlet 2. The dichloromethane content collected in the collection tank is 99% (toluene content 0.5%). Toluene is continuously pumped out from the outlet 3, and the toluene content continuously flowing out from the outlet 3 is 99% (dichloromethane content 0.3%).

[0017] Example 2, separation of a mixture of toluene and DMF; The vacuum degree of the device was controlled to 200 mbar by the vacuum degree control valve above the collection tank, the temperature of the jacket 8 was controlled to 60 ℃ by the water with pre-controlled temperature flowing into the jacket inlet 4 and flowing out of the jacket outlet 5, the stirring paddle speed was 300 rpm / min, the DMF solution containing 40% toluene was continuously transported to the feed inlet 1 at a flow rate of 5 ml / min by the feed pump, toluene was continuously evaporated from the outlet 2, the toluene collected by the collection tank contained 99% toluene (0.2% DMF), and the DMF was continuously flowed out of the outlet 3 by the feed pump, the DMF continuously flowed out of the outlet 3 contained 99% DMF (0.5% toluene).

[0018] It should be noted that the present application is not limited to the examples. According to the scheme of the present application, the examples are changed and modified, or equivalent transformations are made by using the content of the specification and drawings, which are all included in the protection scope of the present application.

Claims

1. A continuous distillation apparatus, characterized by, The whole is cylindrical shape, the inside is sandwich structure, namely the outer cylinder 6 and the inner cylinder 7 nest combination, the outer cylinder 6 and the inner cylinder 7 between sandwich channel 8, the inner cylinder inside middle is provided with the stirring paddle 9, the stirring paddle blade outside close the inner cylinder inner wall;Wherein, the inner cylinder 6 in the top position corresponding to the stirring paddle is provided with the feed inlet 1, and the low boiling point compound discharge port 2 is arranged above the top position corresponding to the stirring paddle, the inner cylinder low part is provided with high boiling point compound discharge port 3, the bottom side of the sandwich channel 8 is provided with the jacket inlet 4, and the upper side of the sandwich channel is provided with the jacket outlet 5; The stirring paddle is driven by the motor, and the rotating speed is controlled, in a certain rotating speed range, with the increase of the rotating speed, the liquid is scraped along the inner wall of the inner cylinder 7, the liquid film is formed on the outer side of the stirring paddle blade, the liquid heating specific surface area is improved, and the distillation efficiency is improved; The inner cylinder 6 is used for flowing the solution to be distilled, and the sandwich channel 8 controls the distillation temperature of the inner cylinder through water bath or oil bath.

2. The continuous distillation apparatus of claim 1, wherein, The device discharge port 2 is connected with the condenser and the low boiling point solvent collection tank outside, the condenser inlet is connected with the device discharge port 2, the condenser outlet is connected with the collection tank, and the vacuum degree control valve is connected above the collection tank; The device controls the vacuum degree of the system through the vacuum degree valve on the collection tank, and the vacuum degree is 20-1000 mbar.

3. The continuous distillation apparatus of claim 1, wherein, The inner diameter of the inner cylinder 7 is 3-100 cm, and the width of the sandwich channel 8 is 2-10 cm.

4. The continuous distillation apparatus of claim 1, wherein, The working process of continuous distillation is as follows: After the solution to be distilled is continuously introduced into the kettle body from the feed inlet 1 by the feed pump, the solution to be distilled is formed into a liquid film along the inner wall of the inner cylinder 7 by the stirring paddle 9 at a certain stirring speed, so as to increase the heating specific surface area of the solution to be distilled;The sandwich channel 8 enters the pre-temperature-controlled water or heat-conducting oil through the inlet 4 to control a certain distillation temperature, and flows out from the jacket channel outlet 5;The low boiling point compound is continuously distilled from the discharge port 2 under normal pressure or reduced pressure, and the high boiling point compound is continuously discharged from the discharge port 3 by the feed pump.

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