A process and equipment for preparing hydroxyethyl methacrylate

Abstract

The invention relates to the technical field of chemical product preparation, and discloses a process and equipment for preparing hydroxyethyl methacrylate. The equipment comprises a reaction container, which is used for containing methacrylic acid liquid and ethylene oxide gas to provide a reaction site; a feed port is installed on the reaction container, which is used for feeding methacrylic acid liquid raw material into the reaction container; a discharge port is also installed on the reaction container, which is used for discharging hydroxyethyl methacrylate product in the reaction container from the reaction container; an air inlet is installed on the reaction container, which is used for injecting ethylene oxide gas raw material into the reaction container; the invention uses an air bag to isolate ethylene oxide from the inert gas after the inert gas is introduced, and stabilizes the air pressure in the reaction container, thereby preventing the ethylene oxide in the reaction container from escaping when the reaction container is opened to pour the methacrylic acid liquid, accurately ensuring that the raw material ratio is not missing, fully reacting, and avoiding the waste of raw materials.

Description

Technical Field

[0001] The invention relates to the field of chemical product preparation, and more specifically, to a process and equipment for preparing hydroxyethyl methacrylate. Background Art

[0002] Hydroxyethyl methacrylate is an important raw material for the production of chemical products and is widely used in polymer modification, coatings, adhesives, textile processing and other fields.

[0003] At present, the preparation process of hydroxyethyl methacrylate includes mixing liquid methacrylic acid and gaseous ethylene oxide for reaction, adding a catalyst and an initiator, stirring and heating, and finally preparing the hydroxyethyl methacrylate product. However, in the above preparation process, it is usually necessary to introduce an inert gas into the reaction chamber to exhaust the air in the reaction chamber to avoid oxidation reaction during the reaction process.

[0004] When the inert gas is filled into the reaction chamber, it is necessary to ensure that the air pressure in the reaction chamber is slightly positive, so that the air pressure in the reaction chamber is greater than the air pressure outside the reaction chamber. At this time, the air pressure in the reaction chamber is greater than the external air pressure, and the inert gas overflows, thereby preventing external air from entering the reaction chamber, so that the reaction chamber is always under the protection of the inert gas; but after the inert gas is introduced into the reaction chamber, in the process of the subsequent reaction raw material-ethylene oxide gas being filled into the reaction chamber, since the reaction raw material-methacrylic acid liquid needs to open the feed end of the reaction chamber to add the reaction raw material, and the air pressure inside the reaction chamber is always greater than the external air pressure, the mixed gas of the inert gas and ethylene oxide in the reaction chamber will escape from the methacrylic acid liquid feed end and the inert gas exhaust port. After ethylene oxide escapes from the reaction chamber, the raw material ratio balance is broken, which will cause insufficient reaction in this preparation process, which not only causes waste of raw materials but also reduces the purity of the product. Summary of the invention

[0005] The invention provides a process and equipment for preparing hydroxyethyl methacrylate, which solves the technical problem in the related art that due to the protection of inert gas in the reaction chamber, ethylene oxide gas escapes from the reaction chamber, resulting in insufficient preparation reaction and reduced purity of the prepared hydroxyethyl methacrylate product.

[0006] The invention provides a device for preparing hydroxyethyl methacrylate, comprising a reaction container for containing methacrylic acid liquid and ethylene oxide gas to provide a reaction site; the reaction container is provided with a feed port for feeding methacrylic acid liquid raw material into the reaction container; the reaction container is also provided with a discharge port for discharging the hydroxyethyl methacrylate product in the reaction container from the reaction container; the reaction container is provided with an air inlet pipe, and a one-way valve is provided in the air inlet pipe for injecting ethylene oxide gas raw material into the reaction container;

[0007] The exhaust pipe is installed on the reaction container and is used to introduce inert gas into the reaction container. A micro-positive pressure single-call valve is installed in the exhaust pipe, and the reaction container is maintained in a micro-positive pressure state before feeding by filling inert gas, wherein the micro-positive pressure state means that the air pressure in the reaction container is greater than the air pressure outside the reaction container;

[0008] A stirring mechanism is installed in the reaction container and is used to mix the methacrylic acid liquid raw material and the ethylene oxide gas raw material in the reaction container;

[0009] A heating mechanism, installed in the reaction vessel, for regulating the temperature change in the reaction vessel during the preparation reaction;

[0010] A detection unit, the detection unit includes a plurality of detection sensors, and the plurality of detection sensors respectively detect the air pressure in the reaction container, the flow rate of the air inlet pipe, and the flow rate of the exhaust pipe;

[0011] A voltage-stabilizing and isolating unit is detachably mounted on one end of the air inlet pipe in the reaction vessel. The voltage-stabilizing and isolating unit comprises an airbag which isolates the air inlet pipe from the inner cavity of the reaction vessel. A puncturing assembly is installed in the reaction vessel. When a predetermined amount of ethylene oxide gas raw material is injected into the airbag, the airbag is inflated. The inflated airbag contacts the puncturing assembly, and the ethylene oxide gas raw material in the airbag enters the inner cavity of the reaction vessel from the air inlet pipe.

[0012] In a preferred embodiment, the voltage stabilizing and isolating unit further comprises a ventilation pipe, one end of which is provided with a bellows, an end of which is away from the ventilation pipe is provided with an annular frame, and the airbag is fixedly embedded inside the annular frame.

[0013] In a preferred embodiment, a threaded section is provided on the outer wall of the vent pipe, an internal thread is provided on the inner wall of the air inlet pipe, and the threaded section is matched with the internal thread.

[0014] In a preferred embodiment, the air inlet pipe includes an upper pipe section and a lower pipe section, which are cooperatively connected, and a snap-fitting piece is detachably installed on the outer side of the connection between the upper pipe section and the lower pipe section. One end of the upper pipe section away from the lower pipe section is connected to an external ethylene oxide gas source, and one end of the lower pipe section away from the upper pipe section extends into the reaction container, and an internal thread is provided on the inner wall of the lower pipe section.

[0015] In a preferred embodiment, the stirring mechanism includes a driving motor, the output end of the driving motor is connected to a first shaft, the first shaft is rotatably arranged on the reaction container, and the end of the first shaft away from the driving motor extends into the reaction container, and a stirring blade is installed on the shaft arm of the first shaft.

[0016] In a preferred embodiment, a container cover is hingedly connected to one side of the reaction container, and a second shaft is rotatably mounted on the container cover, and the second shaft is matched with the first shaft.

[0017] In a preferred embodiment, a slot is provided at the end of the first shaft close to the second shaft, a block is installed at the end of the second shaft close to the first shaft, the slot matches the block, and the second shaft is an electric telescopic rod.

[0018] In a preferred embodiment, a spiral blade is also installed on the shaft arm of the first shaft, and the spiral blade connects two adjacent stirring blades. The piercing component is a sharp spike, and the sharp spike is arranged on the outer side of the stirring blade away from the first shaft. When the first shaft rotates, the rotating stirring blade drives the sharp spike to contact the inflated airbag, thereby piercing the inflated airbag.

[0019] In a preferred embodiment, a vertical anti-wear groove is provided on the outer side of the top end of the ventilation pipe, and the top end of the ventilation pipe exceeds the end of the lower pipe section close to the upper pipe section.

[0020] A process for preparing hydroxyethyl methacrylate specifically comprises the following steps:

[0021] Step 1: Prepare raw materials: prepare methacrylic acid liquid and ethylene oxide gas as reaction raw materials;

[0022] Step 2, pretreatment of the reaction container: continuously introducing an inert gas into the reaction container to exhaust the air in the reaction container, and ensuring that the pressure of the inert gas in the reaction container is maintained in a slightly positive pressure state, wherein the slightly positive pressure state means that the pressure in the reaction container is greater than the pressure outside the reaction container, and the inert gas in the reaction container is discharged to the outside of the reaction container through the methacrylic acid liquid feed port at a preset flow rate to ensure the purity of the reaction environment in the reaction container;

[0023] Step 3, reaction process: a. first add methacrylic acid liquid to the reaction container; b. then add ferric thiocyanate, tetramethylammonium chloride and a little hydroquinone to the reaction container, stir and heat to 90°C; c. finally, introduce ethylene oxide gas into the reaction container, after it is completely introduced, close the air inlet and exhaust ends of the reaction container, react for 2 hours, and then cool the reaction product to 60°C;

[0024] Step 4, obtaining the product: after the reaction time is reached, the pressure in the reaction container is reduced to 0.67 kPa, the product in the reaction container is distilled, and the fraction with a temperature of 86-89° C. and a pressure of 0.67 kPa is collected to obtain a hydroxyethyl methacrylate product;

[0025] Step 5: Product collection and packaging: The obtained hydroxyethyl methacrylate product is collected and packaged for subsequent storage and use.

[0026] The beneficial effect of the present invention is that after the inert gas is introduced, the present invention uses an air bag to isolate ethylene oxide from the inert gas, stabilizes the gas pressure in the reaction container, and then mixes the ethylene oxide in the air bag with the inert gas in the reaction container, thereby preventing the ethylene oxide in the reaction container from escaping when the reaction container is opened and methacrylic acid liquid is poured in, accurately ensuring that the raw material ratio is not missing, fully reacting, and avoiding the waste of raw materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a front view structural schematic diagram of the preparation equipment of the present invention.

[0028] Figure 2 It is a schematic diagram of the front cross-sectional structure of the preparation equipment of the present invention.

[0029] Figure 3 It is a structural schematic diagram of the stirring mechanism of the present invention.

[0030] Figure 4 It is a schematic diagram of the first state of the pressure stabilizing and isolating unit of the present invention in the air intake pipe.

[0031] Figure 5 It is a schematic diagram of the second state of the pressure stabilizing and isolating unit of the present invention in the air intake pipe.

[0032] Figure 6 It is a schematic structural diagram of the voltage stabilizing and isolating unit of the present invention from a first viewing angle.

[0033] Figure 7 It is a schematic structural diagram of the voltage stabilizing and isolating unit of the present invention from a second viewing angle.

[0034] Figure 8 The present invention is a process flow chart for preparing hydroxyethyl methacrylate product.

[0035] In the figure: 1. reaction container; 10. container cover; 11. feed port; 12. discharge port; 13. air inlet pipe; 131. upper pipe section; 132. lower pipe section; 133. engaging member; 14. exhaust pipe; 2. stirring mechanism; 21. driving motor; 22. first shaft; 221. slot; 23. second shaft; 231. block; 24. spiral blade; 25. stirring blade; 3. heating mechanism; 4. detection unit; 5. voltage stabilizing and isolating unit; 51. vent pipe; 52. threaded section; 53. bellows; 54. annular frame; 55. air bag. DETAILED DESCRIPTION

[0036] The subject matter described herein will now be discussed with reference to example embodiments. It should be understood that the discussion of these embodiments is only to enable those skilled in the art to better understand and implement the subject matter described herein, and the functions and arrangements of the elements discussed may be changed without departing from the scope of protection of the contents of this specification. Each example may omit, replace or add various processes or components as needed. In addition, the features described relative to some examples may also be combined in other examples.

[0037] like Figure 1-Figure 7 As shown, a device for preparing hydroxyethyl methacrylate comprises:

[0038] The reaction vessel 1 is used to contain methacrylic acid liquid and ethylene oxide gas to provide a reaction site; the reaction vessel 1 is provided with a feed port 11, which is used to feed methacrylic acid liquid raw material into the reaction vessel 1; the reaction vessel 1 is also provided with a discharge port 12, which is used to discharge the hydroxyethyl methacrylate product in the reaction vessel from the reaction vessel 1; the reaction vessel 1 is provided with an air inlet pipe 13, and a one-way valve is installed in the air inlet pipe 13, which is used to inject ethylene oxide gas raw material into the reaction vessel 1;

[0039] The exhaust pipe 14 is installed on the reaction vessel 1. The exhaust pipe 14 is used to introduce inert gas into the reaction vessel 1. A micro-positive pressure single-call valve is installed in the exhaust pipe 14, and the reaction vessel 1 is maintained in a micro-positive pressure state before feeding by filling with inert gas, wherein the micro-positive pressure state is that the air pressure in the reaction vessel 1 is greater than the air pressure outside the reaction vessel 1;

[0040] A stirring mechanism 2 is installed in the reaction container 1 and is used to mix the methacrylic acid liquid raw material and the ethylene oxide gas raw material in the reaction container 1;

[0041] A heating mechanism 3 is installed in the reaction vessel 1 and is used to control the temperature change in the reaction vessel 1 during the preparation reaction process;

[0042] The detection unit 4 includes a plurality of detection sensors, which respectively detect the air pressure in the reaction container 1, the flow rate of the air inlet pipe 13 and the flow rate of the exhaust pipe 14;

[0043] The voltage-stabilizing and isolating unit 5 is detachably mounted on one end of the air inlet pipe 13 in the reaction vessel 1. The voltage-stabilizing and isolating unit 5 includes an airbag 55. The airbag 55 isolates the air inlet pipe 13 from the inner cavity of the reaction vessel 1. A puncture component is installed in the reaction vessel 1. When a predetermined amount of ethylene oxide gas raw material is injected into the airbag 55, the airbag 55 is inflated. The inflated airbag 55 contacts the puncture component, and the ethylene oxide gas raw material in the airbag 55 enters the inner cavity of the reaction vessel 1 from the air inlet pipe 13.

[0044] It should be noted that the end of the feed port 11 away from the reaction container 1 is connected to the methacrylic acid liquid raw material source; both the feed port 11 and the discharge port 12 are equipped with a one-way valve; the heating mechanism 3 can be a heating structure and method such as an electric heating block or an electric heating wire; the detection sensor includes an air pressure sensor, a flow rate sensor, etc.; the puncturing component can be any sharp object, which can puncture the airbag 55 by movement, for example, the output end of the driving cylinder drives the sharp object to puncture the airbag 55, and then releases the ethylene oxide gas in the airbag 55.

[0045] In this embodiment, the implementation scenario is specifically as follows: first prepare the prepared methacrylic acid liquid and ethylene oxide gas as reaction raw materials; then pretreat the reaction vessel 1: only open the exhaust pipe 14 and the feed port 11 of the reaction vessel 1, and the inert gas source (such as nitrogen, argon, preferably nitrogen - economical and affordable) enters the reaction vessel 1 from the exhaust pipe 14, and the inert gas presses the air in the reaction vessel 1 out from the feed port 11 to ensure the purity of the reaction environment in the reaction vessel 1. After the gas sensor placed at the feed port 11 detects the inert gas with a stable flow rate and the air pressure in the reaction vessel 1 is stabilized to a slightly positive pressure state (the inert gas overflows, thereby preventing external air from entering the reaction vessel 1), the methacrylic acid liquid and the catalyst are poured in from the feed port 11; stir and heat to 90°C, and then introduce ethylene oxide into the reaction vessel 1 through the air inlet pipe 13. After the ethane gas is fully introduced, the ethylene oxide gas expands the airbag 55 to make it in an expanded state, and then the air inlet and exhaust ends of the reaction vessel 1 are closed. At this time, there is only inert gas in the air atmosphere in the reaction vessel 1, and the air pressure in the reaction vessel 1 is always in a slightly positive pressure state. The airbag 55 is punctured by the movement of the puncturing component, and a predetermined amount of ethylene oxide gas in the air inlet pipe 13 enters the reaction vessel 1. The stirring mechanism 2 continues to stir in the reaction vessel 1. After reacting for 2 hours, the reaction product is cooled to 60°C; the feed port 11 is opened, and the air pressure in the reaction vessel 1 is reduced to 0.67 kPa, and the product in the reaction vessel 1 is distilled, and the fraction with a temperature of 86-89°C and an air pressure of 0.67 kPa is collected to obtain a hydroxyethyl methacrylate product, and finally the obtained hydroxyethyl methacrylate product is collected and packaged.

[0046] According to the present invention, after the inert gas is introduced, ethylene oxide gas is firstly charged into the airbag 55, so that ethylene oxide and the inert gas are isolated, part of the inert gas in the reaction container 1 can be discharged, and the gas pressure in the reaction container 1 can be stabilized. Then, the ethylene oxide in the airbag 55 is mixed with the inert gas in the reaction container 1, so that the ethylene oxide in the reaction container 1 is prevented from escaping when the reaction container 1 is opened and methacrylic acid liquid is poured in, and the raw material ratio is accurately guaranteed to be not missing, the reaction is fully carried out, and the waste of raw materials is avoided.

[0047] In one embodiment of the present invention, the voltage stabilizing and isolating unit 5 further comprises a vent pipe 51 , one end of which is provided with a bellows 53 , an end of which is provided with an annular frame 54 away from the vent pipe 51 , and an airbag 55 is fixedly embedded inside the annular frame 54 .

[0048] It should be noted that the provision of the vent pipe 51 and the bellows 53 is conducive to reducing the surface area of ​​the airbag 55, facilitating the reuse of the voltage stabilizing and isolating unit 5, and reducing waste; the bellows 53 is made of a material that does not react with this preparation process, such as metal or rubber resin material.

[0049] In one embodiment of the present invention, a threaded section 52 is formed on the outer wall of the vent pipe 51, and an internal thread is formed on the inner wall of the intake pipe 13, and the threaded section 52 is matched with the internal thread.

[0050] It should be noted that the threaded section 52 is adapted to the internal thread, which makes it easy to remove the pressure stabilizing and isolating unit 5 from the air intake pipe 13 and also makes it easy to recycle the pressure stabilizing and isolating unit 5 .

[0051] In one embodiment of the present invention, the air inlet pipe 13 includes an upper pipe section 131 and a lower pipe section 132, which are cooperatively connected. A snap-fitting part 133 is detachably installed on the outer side of the connection between the upper pipe section 131 and the lower pipe section 132. One end of the upper pipe section 131 away from the lower pipe section 132 is connected to an external ethylene oxide gas source, and one end of the lower pipe section 132 away from the upper pipe section 131 extends into the reaction vessel 1, and an internal thread is provided on the inner wall of the lower pipe section 132.

[0052] It should be noted that the upper pipe section 131 and the lower pipe section 132 are connected by a snap-fitting piece 133, and the snap-fitting piece 133 can also seal the interface between the upper pipe section 131 and the lower pipe section 132. The snap-fitting piece 133 can be in the form of two hinged C-shaped connectors or a flange sealing ring connection.

[0053] It should be further explained that each time the preparation device of the present invention is used for preparation, the reaction vessel 1 needs to be cleaned. Similarly, the voltage stabilizing and isolating unit 5 also needs to be replaced, that is, the structure of the voltage stabilizing and isolating unit 5 is a disposable product.

[0054] It should also be noted that, in consideration of energy conservation and emission reduction and full utilization of various products, the airbag 55 and the annular frame 54 can be set to be fixed in an adhesive manner based on the voltage stabilizing and isolating unit 5 structure of the present invention. Each time the airbag 55 is damaged, the damaged airbag 55 is torn off from the annular frame 54, and then an airbag 55 film is re-adhered, so as to achieve energy conservation and recycling of the structure to a greater extent.

[0055] In one embodiment of the present invention, the stirring mechanism 2 includes a driving motor 21, the output end of the driving motor 21 is connected to a first shaft 22, the first shaft 22 is rotatably disposed on the reaction container 1, and the end of the first shaft 22 away from the driving motor 21 extends into the reaction container 1, and a stirring blade 25 is installed on the shaft arm of the first shaft 22.

[0056] In one embodiment of the present invention, a container cover 10 is hingedly connected to one side of the reaction container 1 , and a second shaft 23 is rotatably mounted on the container cover 10 , and the second shaft 23 is matched with the first shaft 22 .

[0057] In one embodiment of the present invention, a slot 221 is provided at the end of the first shaft 22 close to the second shaft 23, a block 231 is installed at the end of the second shaft 23 close to the first shaft 22, the slot 221 is adapted to the block 231, and the second shaft 23 is an electric telescopic rod.

[0058] In one embodiment of the present invention, a spiral blade 24 is also installed on the shaft arm of the first shaft 22, and the spiral blade 24 connects two adjacent stirring blades 25. The piercing component is a sharp spike, and the sharp spike is arranged on the outer side of the stirring blade 25 away from the first shaft 22. When the first shaft 22 rotates, the rotating stirring blade 25 drives the sharp spike to contact the inflated airbag 55, thereby piercing the inflated airbag 55.

[0059] In one embodiment of the present invention, a vertical anti-wear groove is formed on the outer side of the top end of the ventilation pipe 51 , and the top end of the ventilation pipe 51 exceeds the end of the lower pipe section 132 close to the upper pipe section 131 .

[0060] like Figure 8 As shown, a process for preparing hydroxyethyl methacrylate specifically comprises the following steps:

[0061] Step 1: Prepare raw materials: prepare methacrylic acid liquid and ethylene oxide gas as reaction raw materials;

[0062] Step 2, pretreatment of the reaction container 1: continuously introduce an inert gas into the reaction container 1, exhaust the air in the reaction container 1, and ensure that the pressure of the inert gas in the reaction container 1 is maintained in a slightly positive pressure state, wherein the slightly positive pressure state means that the pressure in the reaction container 1 is greater than the pressure outside the reaction container 1, and the inert gas in the reaction container 1 is discharged to the outside of the reaction container 1 through the methacrylic acid liquid feed port 11 at a preset flow rate to ensure the purity of the reaction environment in the reaction container 1;

[0063] Step 3, reaction process: a. first add methacrylic acid liquid into the reaction vessel 1; b. then add ferric thiocyanate, tetramethylammonium chloride and a little hydroquinone into the reaction vessel 1, stir and heat to 90°C; c. finally, introduce ethylene oxide gas into the reaction vessel 1, after it is completely introduced, close the air inlet and exhaust ends of the reaction vessel 1, react for 2 hours, and then cool the reaction product to 60°C;

[0064] Step 4, obtaining the product: after the reaction time is reached, the pressure in the reaction vessel 1 is reduced to 0.67 kPa, the product in the reaction vessel 1 is distilled, and the fraction with a temperature of 86-89° C. and a pressure of 0.67 kPa is collected to obtain a hydroxyethyl methacrylate product;

[0065] Step 5: Product collection and packaging: The obtained hydroxyethyl methacrylate product is collected and packaged for subsequent storage and use.

[0066] The above describes an embodiment of the present embodiment, but the present embodiment is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present embodiment, ordinary technicians in this field can also make many forms, all of which are within the protection of the present embodiment.

Claims

1. A device for preparing hydroxyethyl methacrylate, characterized in that, include: A reaction container (1) is used to contain methacrylic acid liquid and ethylene oxide gas to provide a reaction site; the reaction container (1) is provided with a feed port (11), the feed port (11) is used to feed methacrylic acid liquid raw material into the reaction container (1); the reaction container (1) is also provided with a discharge port (12), the discharge port (12) is used to discharge hydroxyethyl methacrylate product in the reaction container from the reaction container (1); the reaction container (1) is provided with an air inlet pipe (13), the air inlet pipe (13) is provided with a one-way valve, and is used to inject ethylene oxide gas raw material into the reaction container (1); an exhaust pipe (14), the exhaust pipe (14) being installed on the reaction container (1), the exhaust pipe (14) being used to introduce an inert gas into the reaction container (1), the exhaust pipe (14) being installed with a micro-positive pressure single-call valve, and being filled with inert gas to maintain a micro-positive pressure state in the reaction container (1) before feeding, wherein the micro-positive pressure state means that the air pressure in the reaction container (1) is greater than the air pressure outside the reaction container (1); A stirring mechanism (2) is installed in the reaction container (1), and the stirring mechanism (2) is used to mix the methacrylic acid liquid raw material and the ethylene oxide gas raw material in the reaction container (1); A heating mechanism (3) is installed in the reaction container (1), and the heating mechanism (3) is used to control the temperature change in the reaction container (1) during the preparation reaction process; A detection unit (4), the detection unit (4) comprising a plurality of detection sensors, the plurality of detection sensors respectively detecting the air pressure in the reaction container (1), the flow rate of the air inlet pipe (13) and the flow rate of the exhaust pipe (14); A voltage-stabilizing and isolating unit (5), the voltage-stabilizing and isolating unit (5) being detachably mounted on one end of the air inlet pipe (13) located in the reaction container (1), the voltage-stabilizing and isolating unit (5) comprising an air bag (55), the air bag (55) isolating the air inlet pipe (13) from the inner cavity of the reaction container (1), a puncturing component being mounted in the reaction container (1), and when a predetermined amount of ethylene oxide gas raw material is injected into the air bag (55), the air bag (55) is in an expanded state, the inflated air bag (55) contacts the puncturing component, and the ethylene oxide gas raw material in the air bag (55) enters the inner cavity of the reaction container (1) from the air inlet pipe (13); The voltage stabilizing and isolating unit (5) further comprises a vent pipe (51), one end of the vent pipe (51) being provided with a bellows (53), an end of the bellows (53) being provided with an annular frame (54) away from the vent pipe (51), and the airbag (55) being fixedly embedded inside the annular frame (54); The outer wall of the ventilation pipe (51) is provided with a threaded section (52), the inner wall of the air inlet pipe (13) is provided with an internal thread, and the threaded section (52) is adapted to fit the internal thread; The stirring mechanism (2) comprises a driving motor (21), the output end of the driving motor (21) is connected to a first shaft (22), the first shaft (22) is rotatably arranged on the reaction container (1), and an end of the first shaft (22) away from the driving motor (21) extends into the reaction container (1), and a stirring blade (25) is installed on the shaft arm of the first shaft (22); A spiral blade (24) is also mounted on the shaft arm of the first shaft (22), the spiral blade (24) connecting two adjacent stirring blades (25), the piercing component being a spike, the spike being arranged on the outer side of the stirring blade (25) away from the first shaft (22), and when the first shaft (22) rotates, the rotating stirring blade (25) drives the spike to contact the inflated airbag (55), thereby piercing the inflated airbag (55); The end of the feed port (11) away from the reaction container (1) is connected to a methacrylic acid liquid raw material source; a one-way valve is installed in both the feed port (11) and the discharge port (12); the heating mechanism (3) adopts an electric heating block or an electric heating wire; the detection sensor comprises a pressure sensor and a flow rate sensor; after the inert gas is introduced, ethylene oxide gas is firstly filled into the air bag (55), and while isolating the ethylene oxide from the inert gas, part of the inert gas in the reaction container (1) can be discharged and the air pressure in the reaction container (1) can be stabilized, and then the ethylene oxide in the air bag (55) is mixed with the inert gas in the reaction container (1), thereby preventing the ethylene oxide in the reaction container (1) from escaping when the reaction container (1) is opened to pour the methacrylic acid liquid, accurately ensuring that the raw material ratio is not missing, fully reacting, and avoiding the waste of raw materials.

2. The device for preparing hydroxyethyl methacrylate according to claim 1, characterized in that: The air inlet pipe (13) comprises an upper pipe section (131) and a lower pipe section (132), the upper pipe section (131) and the lower pipe section (132) being connected in cooperation, a clamping piece (133) being detachably mounted on the outer side of the connection between the upper pipe section (131) and the lower pipe section (132), one end of the upper pipe section (131) away from the lower pipe section (132) being connected to an external ethylene oxide gas source, one end of the lower pipe section (132) away from the upper pipe section (131) extending into the reaction container (1), and the internal thread being arranged on the inner wall of the lower pipe section (132).

3. A device for preparing hydroxyethyl methacrylate according to claim 2, characterized in that, A container cover (10) is hingedly connected to one side of the reaction container (1), and a second shaft (23) is rotatably mounted on the container cover (10), wherein the second shaft (23) is adapted to fit the first shaft (22).

4. The device for preparing hydroxyethyl methacrylate according to claim 3, characterized in that: A clamping groove (221) is provided at the end of the first shaft (22) close to the second shaft (23), a clamping block (231) is installed at the end of the second shaft (23) close to the first shaft (22), the clamping groove (221) is matched with the clamping block (231), and the second shaft (23) is an electric telescopic rod.

5. The device for preparing hydroxyethyl methacrylate according to claim 4, characterized in that: A vertical anti-wear groove is provided on the outer side of the top end of the ventilation pipe (51), and the top end of the ventilation pipe (51) extends beyond the end of the lower pipe section (132) close to the upper pipe section (131).

6. A process for preparing hydroxyethyl methacrylate using an apparatus for preparing hydroxyethyl methacrylate according to claim 5, characterized in that: The following steps are involved: Step 1: Prepare raw materials: prepare methacrylic acid liquid and ethylene oxide gas as reaction raw materials; Step 2, pretreatment of the reaction container (1): continuously introducing an inert gas into the reaction container (1), exhausting the air in the reaction container (1), and ensuring that the gas pressure of the inert gas in the reaction container (1) is maintained in a slightly positive pressure state, wherein the slightly positive pressure state means that the gas pressure in the reaction container (1) is greater than the gas pressure outside the reaction container (1), and the inert gas in the reaction container (1) is discharged to the outside of the reaction container (1) through the methacrylic acid liquid feed port (11) at a preset flow rate, so as to ensure the purity of the reaction environment in the reaction container (1); Step 3, reaction process: a. first add methacrylic acid liquid to the reaction container (1); b. then add ferric thiocyanate, tetramethylammonium chloride and hydroquinone to the reaction container (1), stir and heat to 90°C; c. finally, introduce ethylene oxide gas into the reaction container (1), and after the ethylene oxide gas is completely introduced, close the air inlet and exhaust ends of the reaction container (1), react for 2 hours, and then cool the reaction product to 60°C; Step 4, obtaining the product: after the reaction time is reached, the pressure in the reaction container (1) is reduced to 0.67 kPa, and the product in the reaction container (1) is distilled, and the fraction with a temperature of 86-89° C. and a pressure of 0.67 kPa is collected to obtain a hydroxyethyl methacrylate product; Step 5: Product collection and packaging: The obtained hydroxyethyl methacrylate product is collected and packaged for subsequent storage and use.

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