An extraction separation apparatus for recovering propylene oxide methyl ether and method of use

Abstract

The present application relates to a kind of for recycling epoxy propane methyl ether extraction separation device and use method, belong to epoxy propane byproduct recovery technical field, including extraction column, its side top and bottom are respectively provided with heavy liquid feed pipe and light liquid feed pipe, its top and bottom are respectively provided with light liquid production pipe and heavy liquid production pipe, its top is also provided with driving motor, its inside is provided with shaft, carousel, fixed ring, the side of extraction column is provided with collection cavity, connection pipe is connected between collection cavity and extraction column, the outside of collection cavity is provided with mixed liquid chamber, collection cavity and mixed liquid chamber are connected by first drainage pipe, first extraction pump, second drainage pipe, mixed liquid chamber and extraction column are connected by third drainage pipe, second extraction pump, fourth drainage pipe, fourth drainage pipe is connected to the middle part of extraction column, the present application has the following beneficial effects: byproduct methyl ether in waste water is efficiently recovered, effectively reduce device steam consumption, save production cost.

Description

Technical Field

[0001] This invention relates to the field of propylene oxide by-product recovery technology, and in particular to an extraction and separation device and method for recovering propylene oxide methyl ether. Background Technology

[0002] Propylene oxide, also known as propylene oxide, methyl ethylene oxide, or 1,2-propylene oxide, is an organic compound with the chemical formula C3H6O and is a very important raw material for organic compounds. The byproduct wastewater generated during the propylene oxide production process contains monomethyl ether and isomethyl ether, which need to be recovered. Current technologies generally employ quadruple-effect evaporation to recover monomethyl ether and isomethyl ether. High-temperature steam evaporates the water from the wastewater, recovering the alcohols. To improve steam utilization efficiency, the evaporation temperature and pressure need to be increased, thus leading to high energy consumption.

[0003] To reduce energy consumption and steam usage, liquid-liquid extraction is also used to recover monomethyl ether and isomethyl ether from ether-containing wastewater. This method typically uses an extraction tower, where light and heavy liquids enter from the bottom and top of the tower, respectively, and come into countercurrent contact. This allows monomethyl ether and isomethyl ether to transfer from the wastewater to the extractant. Subsequently, the light liquid is collected from the top of the tower, and the heavy liquid is collected from the bottom.

[0004] In existing extraction columns, both light and heavy liquids are continuously fed into the column while simultaneously being continuously extracted. By setting an appropriate feed rate, the feed and discharge within the column can be kept in balance, allowing the extraction column to operate continuously.

[0005] While theoretically, the extraction tower can operate continuously by balancing the feed and discharge rates, in practice, due to various external factors, the feed rate cannot be perfectly maintained at a constant value and will inevitably fluctuate. When the feed rate of light or heavy liquid is faster than the predetermined rate, the content of light or heavy liquid in the tower will increase during this period, thereby disrupting the original balance. This will cause another liquid to be mixed in with the extracted light or heavy liquid, resulting in a decrease in the purity of the recovered product. This problem urgently needs to be solved. Summary of the Invention

[0006] The purpose of this invention is to provide an extraction and separation device for recovering propylene oxide methyl ether, which has the characteristic of improving product purity.

[0007] The above-mentioned technical objective of the present invention is achieved through the following technical solution: an extraction and separation device for recovering propylene oxide methyl ether, comprising an extraction tower, wherein a heavy liquid feed pipe and a light liquid feed pipe are respectively arranged on the upper and lower sides of the tower, a light liquid collection pipe and a heavy liquid collection pipe are respectively arranged on the top and bottom of the tower, and a drive motor is also arranged on the top of the tower. The tower is internally provided with a rotating shaft, a turntable and a fixing ring. A collection chamber is arranged on the side of the extraction tower, and a connecting pipe is connected between the collection chamber and the extraction tower. A mixing chamber is arranged outside the collection chamber. The collection chamber and the mixing chamber are connected through a first guide pipe, a first extraction pump and a second guide pipe. The mixing chamber is connected to the extraction tower through a third guide pipe, a second extraction pump and a fourth guide pipe. The fourth guide pipe is connected to the middle of the extraction tower. A stirring mechanism is arranged in the mixing chamber.

[0008] Preferably, the collection chamber is arranged circumferentially along the extraction tower, and the number of connecting pipes is multiple and distributed circumferentially along the extraction tower.

[0009] Preferably, the mixing chamber is arranged circumferentially along the collecting chamber, and the stirring mechanism includes a stirring ring arranged circumferentially along the collecting chamber, with stirring blades arranged on both sides of the stirring ring. The stirring mechanism also includes an annular hanging rail arranged at the top of the mixing chamber, which is connected to the stirring ring. The stirring mechanism is connected to a drive mechanism for driving its movement.

[0010] Preferably, the drive mechanism includes a simple clutch mechanism, a stirring shaft, and a gear, all located on one side of the drive motor. The simple clutch mechanism is connected to the drive motor and the stirring shaft, respectively. The stirring shaft is connected to the gear, and a ring rack is provided on the stirring mechanism. The gear meshes with the ring rack.

[0011] Preferably, the simplified clutch mechanism includes a flywheel, friction plates, a drive shaft, and an electric push rod. The flywheel is connected to the power output end of the drive motor. A fixed plate is fixedly installed above the flywheel. The electric push rod is hinged to the lower surface of the fixed plate. A fixing member is connected to the bottom of the fixed plate. The drive shaft is set along the center of the flywheel and rotatably connected to the fixed plate. The end of the drive shaft extends to the center of the flywheel but does not contact the flywheel. The end of the drive shaft is provided with teeth. The friction plates are slidably sleeved on the drive shaft and mesh with the teeth. A release bearing is also sleeved on the drive shaft. The movable end of the release bearing is fixedly connected to the friction plates. A connecting fork is hinged to the fixed end of the release bearing. The other end of the connecting fork is hinged to the power output end of the electric push rod. The middle part of the connecting fork is hinged to the fixing member. The drive shaft and the stirring shaft are connected by a belt and a pulley.

[0012] Preferably, a pressure sensor is installed inside the extraction tower.

[0013] Preferably, a liquid level sensor is installed in the collection chamber.

[0014] Preferably, a pressure control valve is installed on the connecting pipe.

[0015] Another object of the present invention is to provide a method for using an extraction and separation apparatus for recovering propylene oxide methyl ether, comprising the following steps:

[0016] Step 1: Start-up. The extraction tower enters the operating state. The heavy liquid feed pipe and the light liquid feed pipe continuously feed the material, and the heavy liquid outlet pipe and the light liquid outlet pipe continuously discharge the material. The extraction tower reaches a state of equilibrium.

[0017] Step 2: Collection. When the pressure inside the extraction tower exceeds the preset value, open the connecting pipe to guide the liquid in the middle of the extraction tower into the collection chamber, so that the pressure inside the extraction tower can be restored.

[0018] Step 3: Recovery. When the amount of liquid in the collection chamber reaches the preset value, all the liquid is transferred to the mixing chamber.

[0019] Step 4: Mixing. Stir and mix the liquid in the mixing chamber to mix the light liquid with the heavy liquid and to ensure that the light liquid and the heavy liquid are in full contact.

[0020] Step 5: Reflux. The liquid in the mixing chamber is returned to the middle of the extraction tower. During this process, the feed rates of the light liquid and the heavy liquid are reduced to ensure that the pressure inside the extraction tower meets the design standards.

[0021] In summary, the present invention has the following beneficial effects:

[0022] This invention monitors the pressure inside the extraction tower in real time. When the feed rate of the light liquid or heavy liquid exceeds a preset value, the liquid inside the extraction tower is discharged in a timely manner. This prevents the product purity from decreasing because the light liquid is drawn from the heavy liquid collection pipe and the heavy liquid is drawn from the light liquid collection pipe. Therefore, the purity of the product is effectively improved. At the same time, the liquid discharged from the middle of the extraction tower is stirred and mixed, and then returned to the extraction tower from the middle of the extraction tower, so that the light liquid and heavy liquid in this part of the liquid are normally extracted. Attached Figure Description

[0023] Figure 1 This is a structural schematic diagram of Example 1;

[0024] Figure 2 This is a schematic diagram of the structure after the stirring ring is laid out in Example 1;

[0025] Figure 3 yes Figure 1 Enlarged diagram of section A in the middle;

[0026] Figure 4 yes Figure 1 Enlarged schematic diagram of section B.

[0027] In the diagram, 1. Extraction tower; 11. Heavy liquid feed pipe; 12. Light liquid feed pipe; 13. Light liquid collection pipe; 14. Heavy liquid collection pipe; 15. Rotating shaft; 16. Turntable; 17. Fixing ring; 18. Mounting plate; 2. Drive motor; 3. Collection chamber; 31. Connecting pipe; 4. Mixing chamber; 41. First drainage pipe; 42. First extraction pump; 43. Second drainage pipe; 44. Third drainage pipe; 45. Second extraction pump; 46. Fourth drainage pipe; 5. Stirring ring; 51. Stirring blade; 52. Annular hanging rail; 53. Annular rack; 6. Stirring shaft; 61. Gear; 7. Flywheel; 71. Friction plate; 72. Drive shaft; 73. Electric push rod; 74. Fixing plate; 75. Fixing component; 76. Tooth pattern; 77. Separation bearing; 78. Connecting fork; 8. Pressure sensor; 9. Liquid level sensor. Detailed Implementation

[0028] The present invention will be further described in detail below with reference to the accompanying drawings.

[0029] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

[0030] Example 1:

[0031] An extraction and separation device for recovering propylene oxide methyl ether

[0032] like Figure 1 As shown, the extraction tower 1 includes a heavy liquid feed pipe 11 and a light liquid feed pipe 12 connected to the upper and lower sides of its side, respectively. A light liquid collection pipe 13 and a heavy liquid collection pipe 14 are connected to the top and bottom of the extraction tower 1, respectively. Multiple fixing rings 17 are installed along the inner wall of the extraction tower 1, distributed along its height. A mounting plate 18 is fixedly installed above the extraction tower 1, and a drive motor 2 is vertically mounted on the mounting plate 18. The power output end of the drive motor 2 faces downwards and is connected to a rotating shaft 15. The rotating shaft 15 extends along the top of the extraction tower 1 into its interior, and multiple turntables 16 are installed along its length on the rotating shaft 15.

[0033] The working principle is as follows: light liquid enters extraction tower 1 through light liquid feed pipe 12, and heavy liquid enters extraction tower 1 through heavy liquid feed pipe 11. The heavy and light liquids come into countercurrent contact within extraction tower 1, causing the substances to transfer from one phase to the other. Drive motor 2 drives rotating shaft 15 and turntable 16 to rotate, causing the heavy liquid falling on turntable 16 to splash and, under the action of fixing ring 17, fall onto a lower turntable 16, thus ensuring more thorough contact between the light and heavy liquids. The light liquid floats upward to light liquid collection pipe 13 and is collected. The heavy liquid sinks to heavy liquid collection pipe 14 and is collected.

[0034] A collection chamber 3 is arranged circumferentially on the side of the extraction tower 1, enclosing the side of the extraction tower 1. A liquid level sensor 9 is installed inside the collection chamber 3. Multiple connecting pipes 31 are connected between the collection chamber 3 and the extraction tower 1, distributed circumferentially along the side of the extraction tower 1, and located in the middle of the side of the extraction tower 1. Each connecting pipe 31 is equipped with a valve. A pressure sensor 8 is installed inside the extraction tower 1. When the feed rate of the light or heavy liquid is too fast, the pressure sensor 8 detects that the pressure inside the extraction tower 1 exceeds a preset value, opens the valve on the connecting pipe 31, and allows the liquid in the extraction tower 1 to flow into the collection chamber 3. When the pressure inside the extraction tower 1 reaches the preset value, the valve on the connecting pipe 31 is closed.

[0035] In another embodiment of the present invention, there is no need to install a pressure sensor 8 in the extraction tower 1. Instead, the valve in the connecting pipe 31 is replaced with a pressure control valve. When the pressure in the extraction tower 1 exceeds a preset value, the pressure control valve on the connecting pipe 31 automatically opens.

[0036] A mixing chamber 4 is provided outside the collecting chamber 3, surrounding the collecting chamber 3 circumferentially. The collecting chamber 3 and the mixing chamber 4 are connected by a first guide pipe 41, a first extraction pump 42, and a second guide pipe 43, with the first guide pipe 41 extending to the bottom of the collecting chamber 3. The mixing chamber 4 is connected to the extraction tower 1 by a third guide pipe 44, a second extraction pump 45, and a fourth guide pipe 46, with the third guide pipe 44 connected to the bottom of the mixing chamber 4 and the fourth guide pipe 46 connected to the middle of the extraction tower 1.

[0037] The mixing chamber 4 is equipped with such Figure 3 The stirring mechanism shown includes a stirring ring 5, which is annular and located within the mixing chamber 4. The stirring ring 5 has the following features on both sides: Figure 2 The stirring blade 51 is shown. An annular hanging rail 52 is installed on the top wall of the mixing chamber 4, and the annular hanging rail 52 is connected to the stirring ring 5. An annular toothed rack 53 is also provided on the side of the stirring ring 5.

[0038] The stirring mechanism is connected to a drive mechanism, including a simple clutch mechanism, a stirring shaft 6, and a gear 61. One end of the stirring shaft 6 is rotatably connected to the mounting plate 18, and the other end extends downward into the mixing chamber 4 and is rotatably connected to the side wall of the mixing chamber 4. The lower end of the stirring shaft 6 is connected to the gear 61, which meshes with the annular rack 53.

[0039] like Figure 4As shown, a fixed plate 74 is fixedly mounted on top of the mounting plate 18. The simple clutch mechanism includes a drive shaft 72, a friction plate 71, a flywheel 7, and an electric push rod 73. The flywheel 7 is rotatably connected to the mounting plate 18, and is connected to the power output end of the drive motor 2 via a belt and pulley. The upper surface of the flywheel 7 has a friction surface. The drive shaft 72 is rotatably connected to the fixed plate 74, and is perpendicular to the center point of the flywheel 7. The lower end of the drive shaft 72 extends downward to the center point of the flywheel 7. The flywheel 7 has a hole in its center, and the drive shaft 72 is inserted into the hole in the center of the flywheel 7 without contacting the flywheel 7. The lower side of the drive shaft 72 is provided with teeth 76, and the friction plate 71 is slidably connected to the part of the drive shaft 72 with teeth 76 and engages with the teeth 76. A release bearing 77 is sleeved on the drive shaft 72, and there is a certain amount of play between the release bearing 77 and the drive shaft 72, so they do not contact each other. The movable end of the release bearing 77 is fixedly connected to the friction plate 71, and the fixed end of the release bearing 77 is connected to a connecting fork 78. The other end of the connecting fork 78 is hinged to the power output end of the electric push rod 73. The electric push rod 73 is hinged to the bottom surface of the fixed plate 74. A rod-shaped fixing member 75 is fixedly connected to the bottom surface of the fixed plate 74, and the fixing member 75 is hinged to the middle of the connecting fork 78. The drive shaft 72 is connected to the stirring shaft 6 via a belt and pulley.

[0040] When it is necessary to stir the liquid in the mixing chamber 4, the electric push rod 73 pulls the end of the connecting fork 78 upward, causing the other end of the connecting fork 78 to move downward, driving the release bearing 77 and friction plate 71 to move downward, so that the friction plate 71 contacts the flywheel 7. The friction force generated by the contact between the two drives the transmission shaft 72 to rotate, which in turn drives the stirring shaft 6 to rotate. The stirring shaft 6 drives the gear 61 to rotate, and the gear 61 drives the ring rack 53 to rotate, which in turn drives the stirring ring 5 and stirring blade 51 to rotate, stirring the liquid in the mixing chamber 4, mixing the liquid in the mixing chamber 4, and making the light liquid and heavy liquid fully contact each other.

[0041] Example 2:

[0042] A method of using an extraction and separation device for recovering propylene oxide methyl ether

[0043] Step 1: Start-up. Extraction tower 1 enters the working state. Heavy liquid feed pipe 11 and light liquid feed pipe 12 continuously feed, while heavy liquid outlet pipe 14 and light liquid outlet pipe 13 continuously discharge. The extraction tower 1 reaches a state of equilibrium.

[0044] Step 2: Collection. When the pressure inside the extraction tower 1 exceeds the preset value, open the connecting pipe 31 to introduce the liquid in the middle of the extraction tower 1 into the collection chamber 3, so that the pressure inside the extraction tower 1 can be restored.

[0045] Step 3: Recovery. When the amount of liquid in the collection chamber 3 reaches the preset value, all the liquid is transferred to the mixing chamber 4.

[0046] Step 4: Mixing. Stir and mix the liquid in mixing chamber 4 to mix the light liquid with the heavy liquid and to ensure that the light liquid and the heavy liquid are in full contact.

[0047] Step 5: Reflux. The liquid in the mixing chamber 4 is returned to the middle of the extraction tower 1. During this process, the feed rates of the light liquid and the heavy liquid are reduced to ensure that the pressure inside the extraction tower 1 meets the design standards.

Claims

1. An extraction and separation device for recovering dimethyl ether from a byproduct of propylene oxide production, comprising an extraction tower (1), wherein a heavy liquid feed pipe (11) and a light liquid feed pipe (12) are respectively arranged on the upper and lower sides of the tower, a light liquid outlet pipe (13) and a heavy liquid outlet pipe (14) are respectively arranged on the top and bottom of the tower, a drive motor (2) is also arranged on the top of the tower, and a rotating shaft (15), a rotating disk (16), and a fixing ring (17) are arranged inside the tower, characterized in that, A collection chamber (3) is provided on the side of the extraction tower (1). A connecting pipe (31) is connected between the collection chamber (3) and the extraction tower (1). A mixing chamber (4) is provided outside the collection chamber (3). A first guide pipe (41), a first extraction pump (42), and a second guide pipe (43) are connected in sequence between the collection chamber (3) and the mixing chamber (4). The first guide pipe (41) extends to the bottom of the collection chamber (3). A third guide pipe (44), a second extraction pump (45), and a fourth guide pipe (46) are connected in sequence between the mixing chamber (4) and the extraction tower (1). The third guide pipe (44) is connected to the bottom of the mixing chamber (4), and the fourth guide pipe (46) is connected to the middle of the extraction tower (1). A stirring mechanism is provided in the mixing chamber (4).

2. The extraction and separation device for recovering dimethyl ether from propylene oxide production byproducts according to claim 1, characterized in that, The collection chamber (3) is arranged around the circumference of the extraction tower (1), and there are multiple connecting pipes (31) distributed around the circumference of the extraction tower (1).

3. The extraction and separation device for recovering dimethyl ether from propylene oxide production byproducts according to claim 1, characterized in that, The mixing chamber (4) is arranged around the circumference of the collecting chamber (3). The stirring mechanism includes a stirring ring (5) arranged around the circumference of the collecting chamber (3). Stirring blades (51) are arranged on both sides of the stirring ring (5). The stirring mechanism also includes an annular hanging rail (52) arranged at the top of the mixing chamber (4). The annular hanging rail (52) is connected to the stirring ring (5). The stirring mechanism is connected to a driving mechanism for driving its movement.

4. The extraction and separation device for recovering dimethyl ether from propylene oxide production byproducts according to claim 3, characterized in that, The drive mechanism includes a simple clutch mechanism, a stirring shaft (6), and a gear (61) located on one side of the drive motor (2). The simple clutch mechanism is connected to the drive motor (2) and the stirring shaft (6) respectively. The stirring shaft (6) is connected to the gear (61). A ring rack (53) is provided on the stirring mechanism. The gear (61) meshes with the ring rack (53).

5. An extraction and separation device for recovering dimethyl ether from a byproduct of propylene oxide production according to claim 4, characterized in that, The simple clutch mechanism includes a flywheel (7), friction plates (71), a drive shaft (72), and an electric push rod (73). The flywheel (7) is connected to the power output end of the drive motor (2). A fixed plate (74) is fixedly installed above the flywheel (7). The electric push rod (73) is hinged to the lower surface of the fixed plate (74). A fixing piece (75) is connected to the bottom of the fixed plate (74). The drive shaft (72) is set along the center of the flywheel (7) and rotatably connected to the fixed plate (74). The end of the drive shaft (72) extends to the center of the flywheel (7) but does not contact the flywheel (7). The end of the shaft (72) is provided with teeth (76), the friction plate (71) is slidably sleeved on the drive shaft (72) and meshes with the teeth (76), the drive shaft (72) is also sleeved with a release bearing (77), the movable end of the release bearing (77) is fixedly connected to the friction plate (71), the fixed end of the release bearing (77) is hinged with a connecting fork (78), the other end of the connecting fork (78) is hinged to the power output end of the electric push rod (73), the middle part of the connecting fork (78) is hinged to the fixing member (75), and the drive shaft (72) and the stirring shaft (6) are connected by a belt and a pulley.

6. The extraction and separation apparatus for recovering dimethyl ether from propylene oxide production byproducts according to claim 1, characterized in that, A pressure sensor (8) is installed inside the extraction tower (1).

7. An extraction and separation apparatus for recovering dimethyl ether from a byproduct of propylene oxide production according to claim 1, characterized in that, A liquid level sensor (9) is installed in the collection chamber (3).

8. An extraction and separation device for recovering dimethyl ether from a byproduct of propylene oxide production according to claim 1, characterized in that, A pressure control valve is installed on the connecting pipe (31).

9. A method of using an extraction and separation device for recovering dimethyl ether from a byproduct of propylene oxide production, characterized in that, Using the apparatus as described in claim 8 includes the following steps: Step 1: Start-up. The extraction tower (1) enters the working state. The heavy liquid feed pipe (11) and the light liquid feed pipe (12) continuously feed the material, and the heavy liquid outlet pipe (14) and the light liquid outlet pipe (13) continuously discharge the material. The extraction tower (1) reaches a balanced state. Step 2: Collection. When the pressure inside the extraction tower (1) exceeds the preset value, open the pressure control valve on the connecting pipe (31) to introduce the liquid in the middle of the extraction tower (1) into the collection chamber (3) to restore the pressure inside the extraction tower (1). Step 3: Recovery. When the amount of liquid in the collection chamber (3) reaches the preset value, all the liquid is transferred to the mixing chamber (4). Step 4: Mixing. Stir and mix the liquid in the mixing chamber (4) to mix the light liquid with the heavy liquid and make the light liquid and heavy liquid fully contact each other. Step 5: Reflux. The liquid in the mixing chamber (4) is returned to the middle of the extraction tower (1). During this process, the feed rates of the light liquid and the heavy liquid are reduced to ensure that the pressure inside the extraction tower (1) meets the design standards.

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