A continuous separation apparatus for a mixture of ethanol and n-butyraldehyde

Abstract

The application provides a continuous separation device for ethanol and n-butyl aldehyde mixture, and belongs to the technical field of compound separation devices. The device comprises a negative pressure tank, a liquid supply pipe, a liquid outlet pipe, a rotating shaft, a negative pressure connecting pipe, the liquid supply pipe and the liquid outlet pipe are connected to the upper and lower ends of the negative pressure tank respectively, the rotating shaft is rotationally connected in the liquid supply pipe and the liquid outlet pipe, two valve structures are respectively arranged between the rotating shaft and the liquid supply pipe and between the rotating shaft and the liquid outlet pipe, the valve structure comprises a rotating block fixed on the rotating shaft and a fixed block, a through hole one is formed in the rotating block, a through hole two is formed in the fixed block, the through hole one and the through hole two of the same valve structure are in the open state when they are opposite to each other, a temporary cavity one is formed between the two valve structures in the liquid supply pipe, a temporary cavity two is formed between the two valve structures in the liquid outlet pipe, the rotating shaft is driven by a speed reducer motor, and the negative pressure connecting pipe is connected between the gas inlet end of a vacuum pump and the inner cavity of the negative pressure tank. The application has the advantages of low separation cost and high efficiency.

Description

Technical Field

[0001] This invention belongs to the technical field of compound separation equipment, and relates to a continuous separation device for a mixture of ethanol and n-butyraldehyde. Background Technology

[0002] n-propyldioxane and oxazole react under high temperature conditions to produce a cyclic adduct. The cyclic adduct produces ethanol and n-butyraldehyde during the conversion of vitamin B6. However, n-butyraldehyde is the main raw material for the production of heptacyclic compounds. Therefore, in the subsequent processes of the above process, n-butyraldehyde and ethanol need to be separated so that they can be recycled and reused.

[0003] As is well known, at room temperature, the boiling points of n-butyraldehyde and ethanol are very close, both around 78 degrees Celsius, and they are miscible and have the same phase properties at room temperature. Therefore, they can only be separated using traditional thermodynamic processes such as distillation and fractionation. Extraction, filtration, and crystallization are not suitable for the needs of continuous production lines. Therefore, how to continuously separate these two compounds online is of positive significance for production efficiency and quality. Summary of the Invention

[0004] The purpose of this invention is to address the aforementioned problems in existing technologies by providing a continuous separation device for a mixture of ethanol and n-butyraldehyde. The technical problem to be solved by this invention is how to achieve continuous separation of ethanol and n-butyraldehyde.

[0005] The objective of this invention can be achieved through the following technical solution: A continuous separation device for a mixture of ethanol and n-butyraldehyde includes a negative pressure tank, a supply pipe, an outlet pipe, a rotating shaft, and a negative pressure connection pipe. The supply pipe and the outlet pipe are respectively connected to the upper and lower ends of the negative pressure tank. The rotating shaft is rotatably connected inside the supply pipe and the outlet pipe. Two valve structures are respectively arranged between the rotating shaft and the supply pipe, and between the rotating shaft and the outlet pipe. Each valve structure includes a rotating block fixed on the rotating shaft and a fixing block. The fixing block of the valve structure located inside the supply pipe is fixed to the inner wall of the supply pipe, and the fixing block of the valve structure located inside the outlet pipe is fixed to the inner wall of the outlet pipe. A through hole is provided on the rotating block, and a through hole is provided on the fixing block. There is a second through hole. When the first through hole and the second through hole of the same valve structure are connected, the valve structure is in the open state. During the rotation of the shaft, the valve structure at the end of the supply pipe near the negative pressure tank and the valve structure at the end of the outlet pipe near the negative pressure tank open simultaneously. The valve structure at the end of the supply pipe away from the negative pressure tank and the valve structure at the end of the outlet pipe away from the negative pressure tank open simultaneously. The two valve structures in the supply pipe and the two valve structures in the outlet pipe do not open simultaneously. A temporary storage chamber 1 is formed between the two valve structures in the supply pipe, and a temporary storage chamber 2 is formed between the two valve structures in the outlet pipe. The shaft is driven by a geared motor, and the negative pressure pipe is connected to the air inlet of a vacuum pump and the inner cavity of the negative pressure tank.

[0006] Furthermore, a flow guide disc is fixedly installed on the rotating shaft inside the negative pressure tank; the diameter of the flow guide disc is larger than the inner diameter of the liquid supply pipe, and the flow guide disc is located directly below the liquid supply pipe.

[0007] Furthermore, the supply pipe has an extension located inside the negative pressure tank, and the negative pressure connector is located outside the extension.

[0008] Furthermore, the upper surface of the flow guide turntable has a spiral guide groove, and the outer end of the spiral guide groove is open.

[0009] Furthermore, the separation device also includes an insulation pipe, one end of which is connected to the inner cavity of the negative pressure tank, and the other end of which is connected to a protective gas storage tank. A pressure limiting valve is installed on the insulation pipe, and the middle part of the insulation pipe is spirally embedded in the flow guide turntable.

[0010] Furthermore, the protective gas inside the insulation pipe is carbon dioxide.

[0011] Furthermore, the negative pressure tank is equipped with a temperature sensor and a pressure sensor.

[0012] Under certain constant temperature conditions, there is a pressure difference in the saturated vapor pressure of ethanol. Taking advantage of this property, the mixture is placed in a pressure environment between the two saturated vapor pressures at the specified temperature, so that the one with the higher saturated vapor pressure evaporates first, thus achieving the separation of the two. Attached Figure Description

[0013] Figure 1 This is a three-dimensional structural diagram of the continuous separation equipment.

[0014] Figure 2 This is a cross-sectional view of the continuous separation equipment.

[0015] Figure 3 This is a schematic diagram of the flow guide turntable.

[0016] Figure 4 This is a structural diagram of the two components of the valve structure.

[0017] Figure 5 This is a schematic diagram showing the switching of the four valve structures in the feeding and discharging states.

[0018] In the diagram, 1. Negative pressure tank; 11. Liquid supply pipe; 12. Liquid outlet pipe; 13. Negative pressure connection pipe; 14. Extension section; 2. Rotary shaft; 3. Valve structure; 31. Rotary block; 32. Fixing block; 33. Through hole one; 34. Through hole two; 35. Temporary storage chamber one; 36. Temporary storage chamber two; 4. Gear motor; 5. Guide turntable; 51. Spiral guide groove; 6. Insulation pipe. Detailed Implementation

[0019] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings to further illustrate the technical solutions of the present invention. However, the present invention is not limited to these embodiments.

[0020] like Figures 1 to 4 As shown, the separation device includes a negative pressure tank 1, a liquid supply pipe 11, a liquid outlet pipe 12, a rotating shaft 2, and a negative pressure connection pipe 13. The liquid supply pipe 11 and the liquid outlet pipe 12 are respectively connected to the upper and lower ends of the negative pressure tank 1. The rotating shaft 2 is rotatably connected inside the liquid supply pipe 11 and the liquid outlet pipe 12. Two valve structures 3 are respectively provided between the rotating shaft 2 and the liquid supply pipe 11 and between the rotating shaft 2 and the liquid outlet pipe 12. The valve structure 3 includes a rotating block 31 fixed on the rotating shaft 2 and a fixed block 32 rotatably connected on the rotating shaft 2. The rotating block 31 is sealed with the inner wall of the liquid supply pipe 11 or the liquid outlet pipe 12. A temporary storage chamber 35 is formed between the two valve structures 3 inside the liquid supply pipe 11, and a temporary storage chamber 36 is formed between the two valve structures 3 inside the liquid outlet pipe 12.

[0021] The fixing block 32 of the valve structure 3 located in the liquid supply pipe 11 is fixed on the inner wall of the liquid supply pipe 11. The fixing block 32 of the valve structure 3 located in the liquid outlet pipe 12 is fixed on the inner wall of the liquid outlet pipe 12. The rotating block 31 has a through hole 33 and the fixing block 32 has a through hole 34. When the through hole 33 and the through hole 34 of the same valve structure 3 are connected, the valve structure 3 is in the open state. The four valve structures 3 are in pairs. One group consists of two valve structures 3 close to the negative pressure tank 1, and the other group consists of two valve structures 3 far away from the negative pressure tank 1. There is a phase difference in the opening of the two groups of valve structures 3 to ensure that the rotation of the rotating shaft 2 will not affect the sealing of the negative pressure tank 1.

[0022] The speed of the reduction motor 4 is controlled according to the feeding speed to ensure the retention time and separation rate of the material to be separated in the negative pressure tank 1. The negative pressure pipe 13 connects the air inlet of a vacuum pump to the inner cavity of the negative pressure tank 1.

[0023] A flow guide disc 5 is fixedly mounted on the rotating shaft 2 inside the negative pressure tank 1. The upper surface of the flow guide disc 5 has a spiral guide groove 51 with an open outer end. The diameter of the flow guide disc 5 is larger than the inner diameter of the liquid supply pipe 11, and the flow guide disc 5 is located directly below the liquid supply pipe 11. After the separated liquid falls onto the flow guide disc 5, it is slowly flowed outward as the flow guide disc 5 rotates, eventually falling into the bottom of the negative pressure tank 1 below the flow guide disc 5. The flow guide disc 5 extends the residence time of the liquid to be separated in the negative pressure tank 1 and allows it to "spread out" as much as possible, increasing the vaporization surface area.

[0024] The liquid supply pipe 11 has an extension section 14 located inside the negative pressure tank 1, and the negative pressure connector 13 is located outside the extension section 14. The extension section 14 can prevent the liquid to be separated from splashing, and at the same time, it can make the liquid to be separated fall into the middle of the guide plate 5. In addition, since the liquid falls smoothly onto the guide plate 5 and the falling position is far away from the negative pressure connector 13, the probability of the negative pressure connector 13 sucking away the unseparated liquid particles during the air suction process can be reduced.

[0025] This separation equipment also includes an insulated pipe 6. One end of the insulated pipe 6 is connected to the inner cavity of the negative pressure tank 1, and the other end of the insulated pipe 6 is connected to a protective gas storage tank. A pressure limiting valve is installed on the insulated pipe 6. The middle part of the insulated pipe 6 is spirally embedded in the flow guide turntable 5. The path of the insulated pipe 6 is as follows: it enters the flow guide turntable 5 from the protective gas storage tank and then discharges into the negative pressure tank 1. Since the rotating shaft 2 is a rotating part, the insulated pipe 6 needs to be connected to the rotating shaft 2 through a rotary joint. Specifically, the insulated pipe 6 is buried in the rotating shaft 2, then extends to the flow guide turntable 5, and finally extends out from the outer wall of the rotating shaft 2 above the flow guide turntable 5. The rotary joint is rotatably connected to the lower end of the rotating shaft 2 and connected to the protective gas storage tank. A temperature control structure for the protective gas is set in the protective gas storage tank to keep its temperature below 25 degrees Celsius, offsetting the temperature rise caused by equipment operation, airflow, etc., and ensuring that the temperature in the negative pressure tank 1 is controlled at about 25 degrees Celsius.

[0026] Carbon dioxide is the best protective gas because it is inexpensive and has a relatively large molecular weight, which can better suppress the natural evaporation of the mixed liquid compared to common gases such as air and nitrogen. The flow of protective gas can also increase the gas flow rate from the negative pressure tank 1 to the negative pressure pipe 13, so that the gaseous n-butyraldehyde in the negative pressure tank 1 can be quickly extracted.

[0027] The negative pressure tank 1 is equipped with a temperature sensor and a pressure sensor. These sensors are used to monitor two main environmental indicators inside the negative pressure tank 1. The temperature inside the negative pressure tank 1 is regulated by controlling the temperature of the protective gas entering the negative pressure tank 1. The pressure inside the negative pressure tank 1 is kept within the set range by adjusting the pressure of the vacuum pump, the pressure limit value of the pressure relief valve, and the flow rate of the protective gas in the insulation pipe 6.

[0028] The basic principle of this scheme is: at a temperature of 25℃, the saturated vapor pressure of ethanol is 8±0.2kPa and the saturated vapor pressure of n-butyraldehyde is 14.7±0.2kPa. Utilizing this characteristic, the mixture is placed in a temperature environment and a pressure environment between the two saturated vapor pressures, so that the one with the higher saturated vapor pressure will vaporize and evaporate first. Combined with the structural design of the equipment, continuous and efficient separation can be achieved.

[0029] This scheme limits the separation environment temperature to 25 degrees Celsius because this temperature is close to room temperature, the environmental acquisition cost is low, and the saturated vapor pressure difference between n-butyraldehyde and ethanol is also large at this temperature, almost a multiple of each other. Therefore, the separation cost and separation effect are relatively good under this temperature environment. However, the saturated vapor pressure of n-butyraldehyde and ethanol also differs at other temperature values. Implementing this scheme under other temperature environments does not exceed the scope of this scheme, and it is difficult to achieve the low-cost effect that this scheme can achieve.

[0030] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

Claims

1. A continuous separation apparatus for a mixture of ethanol and n-butyraldehyde, characterized in that, The system includes a negative pressure tank (1), a liquid supply pipe (11), a liquid outlet pipe (12), a rotating shaft (2), and a negative pressure connection pipe (13). The liquid supply pipe (11) and the liquid outlet pipe (12) are respectively connected to the upper and lower ends of the negative pressure tank (1). The rotating shaft (2) is rotatably connected inside the liquid supply pipe (11) and the liquid outlet pipe (12). Two valve structures (3) are respectively provided between the rotating shaft (2) and the liquid supply pipe (11) and between the rotating shaft (2) and the liquid outlet pipe (12). The valve structure (3) includes a rotating block (31) fixed on a rotating shaft (2) and a fixing block (32). The fixing block (32) of the valve structure (3) located in the supply pipe (11) is fixed on the inner wall of the supply pipe (11), and the fixing block (32) of the valve structure (3) located in the outlet pipe (12) is fixed on the inner wall of the outlet pipe (12). The rotating block (31) has a through hole one (33), and the fixing block (32) has a through hole two (34). The same valve structure (3) When the through hole 1 (33) and through hole 2 (34) of the valve are connected, the valve structure (3) is in the open state; during the rotation of the shaft (2), the valve structure (3) at the end of the supply pipe (11) near the negative pressure tank (1) and the valve structure (3) at the end of the outlet pipe (12) near the negative pressure tank (1) open simultaneously, and the valve structure (3) at the end of the supply pipe (11) away from the negative pressure tank (1) and the valve structure (3) at the end of the outlet pipe (12) away from the negative pressure tank (1) open simultaneously. When the liquid supply pipe (11) is opened, the two valve structures (3) in the liquid supply pipe (11) and the two valve structures (3) in the liquid outlet pipe (12) are not opened at the same time; a temporary storage chamber one (35) is formed between the two valve structures (3) in the liquid supply pipe (11) and a temporary storage chamber two (36) is formed between the two valve structures (3) in the liquid outlet pipe (12); the rotating shaft (2) is driven by a geared motor (4), and the negative pressure pipe (13) is connected to the air inlet of a vacuum pump and the inner cavity of the negative pressure tank (1).

2. The continuous separation equipment for a mixture of ethanol and n-butyraldehyde according to claim 1, characterized in that, A flow guide turntable (5) is fixedly installed on the rotating shaft (2) inside the negative pressure tank (1); the diameter of the flow guide turntable (5) is larger than the inner diameter of the liquid supply pipe (11), and the flow guide turntable (5) is located directly below the liquid supply pipe (11).

3. The continuous separation equipment for a mixture of ethanol and n-butyraldehyde according to claim 2, characterized in that, The liquid supply pipe (11) has an extension (14) located inside the negative pressure tank (1), and the negative pressure connector (13) is located outside the extension (14).

4. The continuous separation equipment for a mixture of ethanol and n-butyraldehyde according to claim 2, characterized in that, The upper surface of the flow guide turntable (5) has a spiral guide groove (51), and the outer end of the spiral guide groove (51) is open.

5. A continuous separation apparatus for a mixture of ethanol and n-butyraldehyde according to any one of claims 1-4, characterized in that, This continuous separation equipment also includes a heat-insulating pipe (6), one end of which is connected to the inner cavity of the negative pressure tank (1), and the other end of which is connected to a protective gas storage tank. A pressure limiting valve is provided on the heat-insulating pipe (6), and the middle part of the heat-insulating pipe (6) is spirally embedded in the flow guide turntable (5).

6. The continuous separation apparatus for a mixture of ethanol and n-butyraldehyde according to claim 5, characterized in that, The protective gas inside the insulation pipe (6) is carbon dioxide.

7. A continuous separation apparatus for a mixture of ethanol and n-butyraldehyde according to any one of claims 1-4, characterized in that, The negative pressure tank (1) is equipped with a temperature sensor and a pressure sensor.

Images