A system and device for preparing polymethyl methacrylate

Abstract

The present invention provides a system and device for preparing polymethyl methacrylate. The polymethyl methacrylate preparation device comprises: a reactor, a first material preparation barrel, a second material preparation barrel, a first agitator, a second agitator and a third agitator; the first material preparation barrel is suspended above the reactor, the liquid outlet pipe of the first material preparation barrel is connected to the reactor through a blocking device, the second material preparation barrel is suspended above the reactor and arranged adjacent to the first material preparation barrel, the output pipe of the second material preparation barrel is connected to the reactor, and a first valve is arranged on the output pipe. The system and device for preparing polymethyl methacrylate provided by the present invention can simultaneously complete the dissolution of the dispersant, the dissolution of the auxiliary agent, the dissolution of the initiator and the methyl methacrylate monomer, and the mixed polymerization reaction of each raw material to generate polymethyl methacrylate by using the preparation equipment, thereby simplifying the preparation equipment.

Description

Technical Field

[0001] The invention relates to the field of preparation of polymethyl methacrylate, and in particular to a system and a device for preparing polymethyl methacrylate. Background Art

[0002] Poly(methyl methacrylate) (PMMA) is a high molecular polymer, also known as acrylic or organic glass. It has the advantages of high transparency, low price, and easy machining. It is a commonly used glass substitute material and is widely used in the preparation of transparent materials, medical devices, building materials, handicrafts and other fields.

[0003] At present, the preparation method of PMMA includes suspension polymerization. Suspension polymerization is a polymerization reaction in which methyl methacrylate monomer is suspended in water in the form of small droplets. The raw materials include methyl methacrylate monomer, initiator, dispersant and auxiliary agent, etc. The oily initiator can usually be dissolved with the methyl methacrylate monomer in advance before the reaction. The solid initiator and auxiliary agent are usually dissolved with the solvent first to pre-treat the raw materials before adding them to the reactor. The order of adding the raw materials is to first add deionized water to the reactor, then add the dispersant and auxiliary agent, and finally add the methyl methacrylate monomer dissolved in the initiator.

[0004] At present, the dissolution of methyl methacrylate monomer and initiator, the dissolution of dispersant, the dissolution of auxiliary agent and the final mixing reaction need to be carried out separately using different equipment. There is a lack of completing the dissolution and mixing reaction of the above-mentioned different raw materials through one equipment to simplify the entire preparation system.

[0005] Therefore, it is necessary to provide a system and device for preparing polymethyl methacrylate to solve the above technical problems. Summary of the invention

[0006] The invention provides a system and device for preparing polymethyl methacrylate, which solves the problem in the prior art that one device is lacking for completing the dissolution and mixing reactions of the above-mentioned different raw materials.

[0007] In order to solve the above technical problems, the present invention provides a preparation device for polymethyl methacrylate, comprising: a reaction kettle, a first material preparation cylinder, a second material preparation cylinder, a first stirrer, a second stirrer and a third stirrer;

[0008] The first material making cylinder is suspended above the reactor, and the liquid outlet pipe of the first material making cylinder is connected to the reactor through a plugging device. The second material making cylinder is suspended above the reactor and is arranged adjacent to the first material making cylinder. The output pipe of the second material making cylinder is connected to the reactor, and a first valve is arranged on the output pipe.

[0009] The first agitator is used to stir and mix the reaction raw materials in the reactor, the second agitator is used to stir and mix the raw materials in the first material preparation cylinder, and the third agitator is used to stir and mix the raw materials in the second material preparation cylinder;

[0010] Wherein, the first material preparation cylinder and the second material preparation cylinder are used to pre-treat the raw materials, and the pre-treated raw materials are added into the reactor in sequence.

[0011] Preferably, the polymethyl methacrylate preparation device further comprises a bracket, and the reaction kettle is mounted on the bracket.

[0012] Preferably, the first agitator comprises a first agitating shaft, a first agitating blade and a second one-way bearing, the bottom end of the first agitating shaft is located inside the reactor, and the first agitating blade is installed at the bottom end of the first agitating shaft, the third agitator comprises a third agitating shaft and a third agitating blade, the bottom end of the third agitating shaft is located inside the second material preparation barrel, and the third agitating blade is installed at the bottom end of the third agitating shaft, and a mounting frame is installed on the bracket;

[0013] The polymethyl methacrylate preparation device also includes a driving device and a transmission member, the driving device includes a motor, a first one-way bearing and a driving sleeve, the motor is installed on the mounting frame, the first one-way bearing is installed on the driving shaft of the motor, the driving sleeve is installed at the bottom end of the driving shaft, the top end of the first stirring shaft passes through the top end of the reactor and is connected to the driving sleeve through the second one-way bearing, the first one-way bearing and the second one-way bearing have opposite action directions, the transmission member is drivingly connected to the first one-way bearing and the third stirring shaft, the top end of the third stirring shaft passes through the top end of the second material preparation barrel and is rotatably connected to the mounting frame.

[0014] Preferably, the transmission member includes a transmission belt and two transmission wheels, the two transmission wheels are respectively mounted on the first one-way bearing and the third stirring shaft, and the transmission belt transmission connects the two transmission wheels.

[0015] Preferably, the top end of the first stirring shaft passes through the top end of the reactor and extends to the interior of the material preparation barrel, and is then connected to the driving sleeve through the second one-way bearing. The second agitator includes a second stirring shaft, a second stirring blade, a square sleeve and a lifting piece. The second stirring shaft is sleeved on the first stirring shaft, the square sleeve is installed on the top end of the second stirring shaft and sleeved on the driving sleeve, the second stirring blade is installed on the bottom end of the second stirring shaft, and the lifting piece is used to adjust the height of the second stirring shaft.

[0016] Preferably, the lifting member is a ramp block, the number of the lifting members is two, and the two lifting members are symmetrically mounted at the bottom end of the second stirring shaft;

[0017] The blocking device comprises a mounting shell, two push cylinders, two valve plates and two L-shaped arms. The input end of the mounting shell is connected to the liquid outlet pipe, and the output end of the mounting shell is connected to the reactor. The two push cylinders are installed on the mounting shell at intervals and are located on both sides of the liquid outlet pipe. The two valve plates are symmetrically installed inside the mounting shell. One push cylinder is connected to one valve plate through one L-shaped arm. Semicircular holes are provided on opposite sides of the two valve plates.

[0018] The interior of the liquid outlet pipe is connected with a support sleeve via a connecting rod, and the support sleeve is sleeved on the second stirring shaft and is located below the second stirring blade;

[0019] When the two valve plates are combined, the two valve plates are sleeved on the first stirring shaft, and the valve plates support the second stirring shaft.

[0020] Preferably, the tops of the opposite sides of the two valve plates and the positions corresponding to the lifting members are arranged as inclined surfaces.

[0021] Preferably, a pad is provided at the bottom end of the second stirring blade.

[0022] Preferably, the polymethyl methacrylate preparation device further comprises a condenser, and the air inlet pipe and the reflux pipe of the condenser are both connected to the reaction kettle.

[0023] The invention also provides a polymethyl methacrylate preparation system, comprising a raw material conveying module, the polymethyl methacrylate preparation device, a filtering module and a drying module.

[0024] Compared with the related art, the preparation device of polymethyl methacrylate provided by the present invention has the following advantages:

[0025] Beneficial effects:

[0026] The invention provides a preparation device for polymethyl methacrylate. When working, a dispersant and an auxiliary agent are respectively added into two second material preparation barrels, and a corresponding solvent is added, and a corresponding third agitator is used for stirring to improve the dissolution efficiency and effect. An oily initiator and a methyl methacrylate monomer are added into a first material preparation barrel, and a second agitator is used for stirring and mixing, so that the oily initiator is better dissolved in the methyl methacrylate monomer. After the dispersant and the auxiliary agent are dissolved, a first valve is opened, and the dispersant and the auxiliary agent are added into a reaction kettle accordingly. The first agitator is operated to quickly mix the dissolved dispersant and the auxiliary agent with deionized water, and then the methyl methacrylate monomer dissolved with the initiator is added from the first material preparation barrel into the reaction kettle for polymerization reaction to generate polymethyl methacrylate.

[0027] Therefore, the preparation equipment can simultaneously complete the dissolution of the dispersant, the dissolution of the auxiliary agent, the dissolution of the initiator and the methyl methacrylate monomer, and the mixed polymerization reaction of various raw materials to generate polymethyl methacrylate, thereby simplifying the preparation equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A schematic structural diagram of a device for preparing polymethyl methacrylate provided by the present invention;

[0029] Figure 2 A cross-sectional view of a device for preparing polymethyl methacrylate provided by the present invention;

[0030] Figure 3 for Figure 2 An enlarged schematic diagram of part A is shown;

[0031] Figure 4 for Figure 2 A schematic structural diagram of a second agitator shown;

[0032] Figure 5 for Figure 3 The structural schematic diagram of the valve plate shown;

[0033] Figure 6 A schematic diagram of a state in which the motor driving shaft provided by the present invention rotates the second agitator and the third agitator clockwise;

[0034] Figure 7 A schematic diagram of a state in which the motor driving shaft provided by the present invention rotates the first agitator and the second agitator counterclockwise;

[0035] Figure 8 A schematic diagram of the working state of the first agitator when the valve plate provided by the present invention is opened and the motor driving shaft rotates counterclockwise;

[0036] Fig. 9 A schematic diagram of the working state of the third agitator when the valve plate provided by the present invention is opened and the motor driving shaft rotates clockwise;

[0037] Fig.10 The present invention is a side view of a device for preparing polymethyl methacrylate.

[0038] Numbers in the figure:

[0039] 1. Reactor; 11. Feed pipe; 12. Discharge pipe; 13. Second valve; 14. Support seat;

[0040] 2. Material making cylinder 1; 21. Material inlet pipe; 22. Liquid outlet pipe; 23. Support sleeve; 231. Connecting rod;

[0041] 3. Material making cylinder 2; 31. Feeding pipe; 32. Output pipe; 33. First valve;

[0042] 4. first stirrer; 41. first stirring shaft; 42. first stirring blade; 43. second one-way bearing;

[0043] 5. second agitator; 51. second agitator shaft; 52. second agitator blade; 53. square sleeve; 54. lifting member; 511. ball bearing; 521. cushion block;

[0044] 6. a third stirrer; 61. a third stirring shaft; 62. a third stirring blade;

[0045] 7. driving device; 71. motor; 72. driving shaft; 73. first one-way bearing; 74. driving sleeve;

[0046] 8. Transmission parts; 81. Transmission belt; 82. Transmission wheel;

[0047] 9. Sealing device; 91. Mounting shell; 92. Push cylinder; 93. Valve plate; 94. L-shaped arm; 941. Semicircular hole;

[0048] 10. Bracket; 20. Mounting frame;

[0049] 100. Condenser; 101. Air inlet pipe; 102. Reflux pipe. DETAILED DESCRIPTION

[0050] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0051] The invention provides a device for preparing polymethyl methacrylate.

[0052] Please refer to Figure 1 to Figure 2In one embodiment of the present invention, the polymethyl methacrylate preparation device comprises: a reaction kettle 1, a first material preparation cylinder 2, a second material preparation cylinder 3, a first stirrer 4, a second stirrer 5 and a third stirrer 6;

[0053] The material preparation cylinder 1 2 is suspended above the reactor 1, and the liquid outlet pipe 22 of the material preparation cylinder 1 2 is connected to the reactor 1 through a plugging device 9. The material preparation cylinder 2 3 is suspended above the reactor 1 and is arranged adjacent to the material preparation cylinder 1 2. The output pipe 32 of the material preparation cylinder 2 3 is connected to the reactor 1, and a first valve 33 is arranged on the output pipe 32;

[0054] The first stirrer 4 is used to stir and mix the reaction raw materials in the reactor 1, the second stirrer 5 is used to stir and mix the raw materials in the material preparation cylinder 1 2, and the third stirrer 6 is used to stir and mix the raw materials in the material preparation cylinder 2 3;

[0055] Wherein, the material preparation barrel 1 2 and the material preparation barrel 2 3 are used to pretreat the raw materials, and the pretreated raw materials are added into the reactor 1 in sequence.

[0056] In this embodiment, the number of the preparation barrels 2 3 is two, which are used to dissolve the dispersant and the auxiliary agent respectively, and the preparation barrel 1 2 is used to dissolve the oily initiator and the methyl methacrylate monomer; the corresponding reactor 1 is provided with a feed pipe 11 on the top for adding deionized water, etc., and a discharge pipe 12 is provided at the bottom, and a second valve 13 is provided on the discharge pipe 12. The tops of the preparation barrels 1 2 and 3 are respectively provided with a feed pipe 21 and a feed pipe 31, which can be used to add dispersants and auxiliary agents and corresponding solvents respectively;

[0057] During operation, the dispersant and the auxiliary agent are added to the two preparation barrels 3 respectively, and the corresponding solvent is added, and the corresponding third agitator 6 is used for stirring to improve the dissolution efficiency and effect, and the oily initiator and the methyl methacrylate monomer are added to the preparation barrel 2, and the second agitator 5 is used for stirring and mixing, so that the oily initiator is better dissolved in the methyl methacrylate monomer, wherein, after the dispersant and the auxiliary agent are dissolved, the first valve 33 is opened, and they are added to the reactor 1 accordingly, and the first agitator 4 is operated to quickly mix the dissolved dispersant and auxiliary agent with the deionized water, and then the methyl methacrylate monomer dissolved with the initiator is added from the preparation barrel 2 to the reactor 1, and a polymerization reaction is carried out to generate polymethyl methacrylate;

[0058] Therefore, the preparation equipment can simultaneously complete the dissolution of the dispersant, the dissolution of the auxiliary agent, the dissolution of the initiator and the methyl methacrylate monomer, and the mixed polymerization reaction of various raw materials to generate polymethyl methacrylate, thereby simplifying the preparation equipment.

[0059] Among them, the reactor 1 is also provided with a temperature regulating device, a pressure regulating module, etc. (not shown in the figure), wherein the temperature regulating device includes a heating device, a temperature sensor, etc., and the pressure regulating module is provided with a pressure sensor, and an air intake valve, an exhaust valve, etc. are provided on the reactor 1.

[0060] See also Figure 1 The polymethyl methacrylate preparation device further includes a bracket 10 , and the reaction kettle 1 is installed on the bracket 10 .

[0061] The reactor 1 is installed through the bracket 10 , and the bracket 10 supports the reactor 1 .

[0062] Among them, the material making barrel 1 2 and the material making barrel 2 3 can be connected to the bracket 10 through a fixing frame, or assembled with the mounting frame 20 through a fixing frame (not shown), so as to improve the stability of the material making barrel 1 2 and the material making barrel 2 3 during operation.

[0063] See also Figure 2 In this embodiment, the first agitator 4 includes a first agitating shaft 41, a first agitating blade 42 and a second one-way bearing 43, the bottom end of the first agitating shaft 41 is located inside the reactor 1, and the first agitating blade 42 is installed at the bottom end of the first agitating shaft 41, the third agitator 6 includes a third agitating shaft 61 and a third agitating blade 62, the bottom end of the third agitating shaft 61 is located inside the material preparation barrel 23, and the third agitating blade 62 is installed at the bottom end of the third agitating shaft 61, and the bracket 10 is installed with a mounting frame 20;

[0064] The preparation device of polymethyl methacrylate also includes a driving device 7 and a transmission member 8. The driving device 7 includes a motor 71, a first one-way bearing 73 and a driving sleeve 74. The motor 71 is installed on the mounting frame 20, the first one-way bearing 73 is installed on the driving shaft 72 of the motor 71, and the driving sleeve 74 is installed at the bottom end of the driving shaft 72. The top end of the first stirring shaft 41 passes through the top end of the reactor 1 and is connected to the driving sleeve 74 through the second one-way bearing 43. The first one-way bearing 73 and the second one-way bearing 43 act in opposite directions. The transmission member 8 drives and connects the first one-way bearing 73 and the third stirring shaft 61. The top end of the third stirring shaft 61 passes through the top end of the material preparation barrel 23 and is rotatably connected to the mounting frame 20.

[0065] Here, the first one-way bearing 73 and the second one-way bearing 43 act in opposite directions, which means that when the drive shaft 72 of the motor 71 rotates in one direction, the drive shaft 72 can drive the transmission member 8 to rotate through the first one-way bearing 73, and at this time, the driving sleeve 74 at the bottom end of the drive shaft 72 cannot drive the first stirring shaft 41 to rotate through the second one-way bearing 43. On the contrary, when the drive shaft 72 of the motor 71 rotates in the other direction, the drive shaft 72 cannot drive the transmission member 8 to rotate through the first one-way bearing 73, and the driving sleeve 74 at the bottom end of the drive shaft 72 can drive the first stirring shaft 41 to rotate through the second one-way bearing 43.

[0066] During operation, when the two material preparation barrels 23 dissolve the dispersant and the auxiliary agent, the drive shaft 72 of the motor 71 rotates clockwise, and the drive shaft 72 can drive the corresponding third stirring shaft 61 to rotate through the first one-way bearing 73 and the transmission member 8, and the third stirring shaft 61 drives the third stirring blade 62 to rotate to stir the corresponding dissolving medium, thereby increasing the dissolution speed;

[0067] When the dissolution is completed, the dispersant and the auxiliary agent are added to the reactor 1 accordingly, and after all subsequent raw materials are added to the reactor 1, the driving shaft 72 of the motor 71 drives the driving shaft 74 to rotate counterclockwise. At this time, the driving sleeve 74 drives the first stirring shaft 41 to rotate through the first one-way bearing 73, thereby driving the first stirring blade 42 to rotate, mixing the raw materials and improving the reaction speed and effect.

[0068] One motor 71 can be used to drive the first stirrer 4 and the two third stirrers 6 to work, thereby reducing the use of driving equipment, and the first stirrer 4 and the third stirrers 6 can work independently.

[0069] In this embodiment, the number of the second material making barrels 3 is two, and two corresponding transmission members 8 and first one-way bearings 73 are provided.

[0070] The outer ring of the second one-way bearing 43 is fixedly installed inside the driving sleeve 74 , and the inner ring is fixedly connected to the first stirring shaft 41 .

[0071] In other embodiments, the first stirrer 4 and the third stirrer 6 may also be provided with motors 71 respectively, and the respective motors 71 are connected to the first stirring shaft 41 and the third stirring shaft 61 respectively, so as to drive the first stirring shaft 41 and the third stirring shaft 61 to rotate respectively.

[0072] Please refer again Figure 2 The transmission member 8 includes a transmission belt 81 and two transmission wheels 82 . The two transmission wheels 82 are respectively mounted on the first one-way bearing 73 and the third stirring shaft 61 . The transmission belt 81 transmits and connects the two transmission wheels 82 .

[0073] The two transmission wheels 82 in one transmission member 8 are respectively mounted on the outer ring of the corresponding first one-way bearing 73 and the third stirring shaft 61 , and the transmission belt 81 is connected to the two transmission wheels 82 .

[0074] The transmission wheel 82 and the transmission belt 81 may be gears, toothed belts, or pulleys, belts, or synchronous wheels, synchronous belts, etc.

[0075] See also Figure 2 and Figure 3 In this embodiment, the top end of the first stirring shaft 41 passes through the top end of the reactor 1 and extends to the interior of the material making barrel 2, and is connected to the driving sleeve 74 through the second one-way bearing 43. The second agitator 5 includes a second stirring shaft 51, a second stirring blade 52, a square sleeve 53 and a lifting member 54. The second stirring shaft 51 is sleeved on the first stirring shaft 41. The square sleeve 53 is installed on the top end of the second stirring shaft 51 and sleeved on the driving sleeve 74. The second stirring blade 52 is installed at the bottom end of the second stirring shaft 51. The lifting member 54 is used to adjust the height of the second stirring shaft 51.

[0076] Please refer to Figure 6 When there are raw materials in both the material preparation barrel 1 2 and the material preparation barrel 2 3, the driving shaft 72 of the motor 71 rotates clockwise, and drives the third stirring shaft 61 to rotate through the first one-way bearing 73 and the transmission member 8 to mix the raw materials in the two material preparation barrels 2 3. At the same time, the sleeve 74 drives the second stirring shaft 51 to rotate through the square sleeve 53 to mix the initiator in the material preparation barrel 1 2 with the methyl methacrylate monomer, thereby improving the dissolution speed and effect; at this time, the first stirring shaft 41 does not work.

[0077] See also Figure 7 When the corresponding dispersants and additives in the two material preparation barrels 2 are dissolved, they are added to the reactor 1. At this time, the drive shaft 72 of the motor 71 rotates counterclockwise, and the first stirring shaft 41 rotates to mix the dissolved dispersants and additives with deionized water. At this time, the driving sleeve 74 drives the second stirring shaft 51 to rotate through the square sleeve 53 to continue stirring the initiator dissolved in the methyl methacrylate monomer;

[0078] See also Figure 8 After the dissolved dispersant and additives are mixed with deionized water, and after the methyl methacrylate monomer in which the initiator is dissolved is added to the reaction, the lifting member 54 lowers the second stirring shaft 51 to separate the square sleeve 53 from the driving sleeve. At this time, when the driving shaft 72 of the motor 71 rotates counterclockwise, only the first stirring shaft 41 works to stir the raw materials inside the reactor 1, thereby improving the reaction efficiency and effect.

[0079] That is, the driving device 7 can drive the second agitator 5 and the third agitator 6 to work simultaneously, the first agitator 4 and the second agitator 5 to work simultaneously, and the first agitator 4 to work alone, and can realize stirring in various scenarios corresponding to the steps of adding raw materials.

[0080] In this embodiment, the outer portion of the driving sleeve 74 is adapted to the inner shape of the square sleeve 53 , that is, the cross section is square and the inner cavity of the driving sleeve 74 is circular, which is convenient for installing the second one-way bearing 43 .

[0081] The second stirring shaft 51 is a tubular structure, so it can be sleeved on the first stirring shaft 41. When the first stirring shaft 41 rotates, it cannot directly drive the second stirring shaft 51 to rotate through the sleeve relationship between the two. The rotation of the second stirring shaft 51 can only be driven by the driving sleeve 74 and the square sleeve 53.

[0082] In other embodiments, the second agitator 5 may also be provided with a separate motor 71 connected to the second agitator shaft 51 . In this case, the material preparation barrel 2 is offset from the center of the reaction kettle 1 .

[0083] See also Figure 2 and Figure 3 , please refer to the lifting member 54 which is a slope block, the number of the lifting members 54 is two, and the two lifting members 54 are symmetrically mounted at the bottom end of the second stirring shaft 51;

[0084] The blocking device 9 includes a mounting shell 91, two push cylinders 92, two valve plates 93 and two L-shaped arms 94. The input end of the mounting shell 91 is connected to the liquid outlet pipe 22, and the output end of the mounting shell 91 is connected to the reactor 1. The two push cylinders 92 are installed on the mounting shell 91 at intervals and are located on both sides of the liquid outlet pipe 22. The two valve plates 93 are symmetrically installed inside the mounting shell 91. One push cylinder 92 is connected to one valve plate 93 through one L-shaped arm 94. Semicircular holes 941 are provided on opposite sides of the two valve plates 93.

[0085] The interior of the liquid outlet pipe 22 is connected to a support sleeve 23 via a connecting rod 231. The support sleeve 23 is sleeved on the second stirring shaft 51 and is located below the second stirring blade 52.

[0086] When the two valve plates 93 are combined, the two valve plates 93 are sleeved on the first stirring shaft 41 , and the valve plates 93 support the second stirring shaft 51 .

[0087] When the initiator is dissolved into the methyl methacrylate monomer, the two push cylinders 92 drive the two valve plates 93 to separate through the L-shaped arm 94, so that the liquid outlet pipe 22 is connected to the reactor 1. At this time, the methyl methacrylate monomer dissolved with the initiator is added to the reactor 1 for subsequent polymerization reaction.

[0088] Please refer to Figure 8 When the valve plate 93 is opened, the second stirring shaft 51 loses its support and thus descends due to gravity. The square sleeve 53 separates from the driving sleeve 74, and the second stirring blade 52 falls on the supporting sleeve 23. The inclined surface of the lifting member 54 is still partially aligned with the valve plate 93. Therefore, when the driving shaft 72 of the motor 71 rotates counterclockwise subsequently, only the first stirring shaft 41 works, and the second stirring shaft 51 and the third stirring shaft 61 will not be driven to rotate.

[0089] When the two push cylinders 92 push the two valve plates 93 to close, the valve plates 93 act on the inclined surfaces of the corresponding lifting members 54 to push the lifting members 54 upward, so that the square sleeve 53 is again sleeved on the driving sleeve 74, and the valve plates 93 support the second stirring shaft 51 again.

[0090] Therefore, the position of the second stirring shaft 51 can be adjusted by opening and closing the valve plate 93, thereby adjusting the use state of the second stirring shaft 51, without the need for additional adjustment equipment. Of course, in other embodiments, the lifting member 54 can also be a lifting cylinder, which is installed on the top of the material making barrel 2, and a bearing is sleeved on the top of the second stirring shaft 51. The output end of the lifting cylinder passes through the top of the material making barrel 2 and is connected to the bearing to adjust the height of the second stirring shaft 51.

[0091] The two valve plates 93 are preferably provided with sealing gaskets on opposite sides thereof to ensure the sealing effect when they are combined.

[0092] In this embodiment, a plurality of balls 511 are embedded at the bottom end of the first stirring shaft 41, so as to reduce the friction between the second stirring shaft 51 and the valve plate 93 when the second stirring shaft 51 rotates;

[0093] A semicircular hole 941 is correspondingly provided on the valve plate 93 so that when the two valve plates 93 are closed, they can be correspondingly sleeved on the first stirring shaft 41 .

[0094] See also Figure 5 As a preferred embodiment of the present invention, the top of the two valve plates 93 on the opposite side and the position corresponding to the lifting member 54 are set as an inclined surface.

[0095] By setting the corresponding position of the top of the valve plate 93 as an inclined surface with the same inclination as the inclined surface of the lifting member 54, the inclined surface of the valve plate 93 contacts the inclined surface of the lifting member 54, so that the lifting member 54 can be pushed upward more easily.

[0096] The lifting member 54 is configured as a sloped block and is located inside the liquid outlet pipe 22 . When the second agitator 5 is working, the lifting member 54 rotates accordingly, thereby driving the solution inside the liquid outlet pipe 22 to flow and increasing the dissolution rate of the raw materials inside the liquid outlet pipe 22 .

[0097] See also Figure 3 and Figure 4 As a preferred embodiment of the present invention, a pad 521 is provided at the bottom end of the second stirring blade 52 .

[0098] In this embodiment, a groove is provided below the corresponding pad 521 at the top of the corresponding support sleeve 23. When the second stirring blade 52 falls on the support sleeve 23, the pad 521 is located in the groove, thereby limiting the axial position of the second agitator 5 to prevent the second agitator 5 from rotating due to vibration or the like when the first stirring shaft 41 rotates subsequently, causing the lifting member 54 and the valve plate 93 to be offset.

[0099] A rubber pad is provided at the bottom end of the cushion block 521 to absorb and buffer the impact force caused by the gravity when the second stirring blade 52 falls on the support sleeve 23, so that the second stirring blade 52 falls on the support sleeve 23 more stably.

[0100] The motor 71 rotates an integer number of times each time it works, so that when the second stirring shaft 51 stops, the lifting member 54 can be kept aligned with the valve plate 93.

[0101] Due to the difference in mixing time between different raw materials, dispersants such as cellulose ether need to be stirred at 70-80°C for about 30 minutes to 1 hour, and basic magnesium carbonate needs to be stirred at 60-70°C for about 30 minutes to 1 hour.

[0102] Additives need to be stirred for about 30 minutes or more at room temperature, such as surfactant additives;

[0103] The oily initiator is dissolved in the methyl methacrylate monomer and stirred at room temperature for 10-20 minutes, such as azobisisobutyronitrile;

[0104] That is, the stirring time of the additive and dispersant is longer. The raw materials can be added to the preparation barrel 1 2 and the preparation barrel 2 3 in sequence according to the different stirring times. Fig. 9 In the initial state, the inhibitor, the auxiliary agent and the corresponding solvent can be added to the second material preparation barrel 3 respectively, the driving shaft 72 of the motor 71 rotates clockwise, and the third agitator 6 performs a stirring process. At this time, the valve plate 93 is in an open state, that is, the square sleeve 53 and the driving sleeve 74 are separated, and the second agitator 5 will not work. After stirring for a period of time, the motor 71 stops, and the two valve plates 93 are controlled to close so that the square sleeve 53 and the driving sleeve 74 are assembled. Figure 6In the middle state, the second stirrer 5 and the third stirrer 6 work simultaneously, and after dissolution, the raw materials are added in sequence.

[0105] See also Fig.10 The polymethyl methacrylate preparation device further includes a condenser 100 , and an air inlet pipe 101 and a reflux pipe 102 of the condenser 100 are both connected to the reactor 1 .

[0106] The volatilized methyl methacrylate monomer enters the condenser 100 through the air inlet pipe 101, is condensed by the condenser pipe inside the condenser 100, and then flows back into the reactor 1 through the reflux pipe 102, thereby reducing the waste of raw materials.

[0107] In one embodiment, when multiple auxiliary agents are used, multiple partitions can be set inside a material preparation barrel 2 3 to divide the interior of the material preparation barrel 2 3 into multiple mixing chambers, the third stirring shaft 61 passes through the multiple partitions in sequence, and a third stirring blade 62 is set corresponding to each mixing chamber, and an inlet pipe and an outlet pipe are set on the material preparation barrel 2 3 corresponding to each mixing chamber, and the discharge end of the outlet pipe is connected to the reactor 1.

[0108] The working principle of the system and device for preparing polymethyl methacrylate provided by the present invention is as follows:

[0109] During operation, dispersants and auxiliary agents are added to two material preparation barrels 2 3 respectively, and corresponding solvents are added, and the corresponding third agitator 6 is used for stirring to improve the dissolution efficiency and effect. The oily initiator and methyl methacrylate monomer are added to the material preparation barrel 1 2, and stirred and mixed by the second agitator 5 to make the oily initiator better dissolved in the methyl methacrylate monomer. After the dispersant and auxiliary agent are dissolved, the first valve 33 is opened and added to the reactor 1 accordingly. The first agitator 4 is operated to quickly mix the dissolved dispersant and auxiliary agent with deionized water, and then the methyl methacrylate monomer dissolved with the initiator is added from the material preparation barrel 1 2 to the reactor 1 to carry out polymerization reaction to generate polymethyl methacrylate.

[0110] For details, please refer to Figure 6 When there are raw materials in both the material preparation barrel 1 2 and the material preparation barrel 2 3, the driving shaft 72 of the motor 71 rotates clockwise, and drives the third stirring shaft 61 to rotate through the first one-way bearing 73 and the transmission member 8 to mix the raw materials in the two material preparation barrels 2 3. At the same time, the sleeve 74 drives the second stirring shaft 51 to rotate through the square sleeve 53 to mix the initiator in the material preparation barrel 1 2 with the methyl methacrylate monomer, thereby improving the dissolution speed and effect; at this time, the first stirring shaft 41 does not work.

[0111] See also Figure 7When the corresponding dispersants and additives in the two material preparation barrels 2 are dissolved, they are added to the reactor 1. At this time, the drive shaft 72 of the motor 71 rotates counterclockwise, and the first stirring shaft 41 rotates to mix the dissolved dispersants and additives with deionized water. At this time, the driving sleeve 74 drives the second stirring shaft 51 to rotate through the square sleeve 53 to continue stirring the initiator dissolved in the methyl methacrylate monomer;

[0112] See also Figure 8 When the initiator and the methyl methacrylate monomer are dissolved, the two valve plates 93 are opened, and the methyl methacrylate monomer solution of the dissolved initiator is added to the reactor 1. Since the two valve plates 93 are opened, the second stirring shaft 51 loses support and thus descends due to gravity, and the square sleeve 53 is separated from the driving sleeve 74, and the second stirring blade 52 falls on the supporting sleeve 23. Therefore, when the driving shaft 72 of the motor 71 rotates counterclockwise, only the first stirring shaft 41 works to stir the raw materials in the reactor 1 for polymerization reaction, and will not drive the second stirring shaft 51 and the third stirring shaft 61 to rotate.

[0113] That is, the driving device 7 can respectively drive the second agitator 5 and the third agitator 6 to work simultaneously, the first agitator 4 and the second agitator 5 to work simultaneously, and the first agitator 4 to work alone. When the valve plate 93 is in the open state, the motor 71 rotates clockwise and can only drive the third agitator 6 to rotate, thereby realizing stirring in various scenarios corresponding to the steps of adding raw materials.

[0114] A support seat 14 is installed inside the reactor 1 via a mounting rod. The support seat 14 supports the bottom end of the first stirring shaft 41 to improve the stability of the first stirring shaft 41 .

[0115] A system for preparing polymethyl methacrylate,

[0116] The present invention also provides a polymethyl methacrylate preparation system, comprising a raw material conveying module, the polymethyl methacrylate preparation device, a filtering module and a drying module.

[0117] Among them, the raw material conveying module is used to add the raw materials into the material preparation cylinder 1 2, the material preparation cylinder 2 3 and the reaction kettle 1 respectively;

[0118] Among them, liquid raw materials such as deionized water, solvent and methyl methacrylate monomer are added into corresponding containers through a water pump and a liquid infusion pipeline. For example, one end of the liquid infusion pipeline is connected to the feed pipe 11 of the reactor 1, and the other end is connected to the output end of the water pump, and the input end of the water pump is connected to the deionized water storage pump through a pipeline.

[0119] For powdered solid raw materials, a material pump can be used in the same way, such as one end of the material delivery pipe is connected to the feed pipe 21 of the material making barrel 2, and the other end is connected to the output end of the material pump, and the input end of the material pump is connected to the storage container of the corresponding raw material, etc.

[0120] When there are larger lump raw materials, they can also be added manually by staff.

[0121] The main input end of the filter module is connected to the discharge pipe 12 of the reactor 1. After the production of polymethyl methacrylate is completed, polymethyl methacrylate and impurity solution are introduced into the filter module to filter the polymethyl methacrylate; the connection between the filter module and the discharge pipe 12 can be connected through a water pump and a pipeline.

[0122] The filtered polymethyl methacrylate is dried by a drying module.

[0123] The filtering module may be a plate and frame filter, etc., and the drying module may be an oven, etc.

[0124] Among them, the specific structure of the preparation device of polymethyl methacrylate refers to the above embodiment. Since the preparation system of polymethyl methacrylate adopts all the technical solutions of all the above embodiments, it at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated here one by one.

[0125] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A device for preparing polymethyl methacrylate, characterized in that: include: A reaction kettle, a first material preparation cylinder, a second material preparation cylinder, a first stirrer, a second stirrer and a third stirrer; The first material making cylinder is suspended above the reactor, and the liquid outlet pipe of the first material making cylinder is connected to the reactor through a plugging device. The second material making cylinder is suspended above the reactor and is arranged adjacent to the first material making cylinder. The output pipe of the second material making cylinder is connected to the reactor, and a first valve is arranged on the output pipe. The first agitator is used to stir and mix the reaction raw materials in the reactor, the second agitator is used to stir and mix the raw materials in the first material preparation cylinder, and the third agitator is used to stir and mix the raw materials in the second material preparation cylinder; Wherein, the first material preparation barrel and the second material preparation barrel are used to pre-treat the raw materials, and the pre-treated raw materials are added into the reactor in sequence.

2. The device for preparing polymethyl methacrylate according to claim 1, characterized in that: The polymethyl methacrylate preparation device further comprises a bracket, and the reaction kettle is installed on the bracket.

3. The preparation device of polymethyl methacrylate according to claim 2, characterized in that: The first agitator comprises a first agitating shaft, a first agitating blade and a second one-way bearing, the bottom end of the first agitating shaft is located inside the reactor, and the first agitating blade is installed at the bottom end of the first agitating shaft, the third agitator comprises a third agitating shaft and a third agitating blade, the bottom end of the third agitating shaft is located inside the second material preparation barrel, and the third agitating blade is installed at the bottom end of the third agitating shaft, and a mounting frame is installed on the bracket; The polymethyl methacrylate preparation device also includes a driving device and a transmission member, the driving device includes a motor, a first one-way bearing and a driving sleeve, the motor is installed on the mounting frame, the first one-way bearing is installed on the driving shaft of the motor, the driving sleeve is installed at the bottom end of the driving shaft, the top end of the first stirring shaft passes through the top end of the reactor and is connected to the driving sleeve through the second one-way bearing, the first one-way bearing and the second one-way bearing have opposite action directions, the transmission member is drivingly connected to the first one-way bearing and the third stirring shaft, the top end of the third stirring shaft passes through the top end of the second material preparation barrel and is rotatably connected to the mounting frame.

4. The preparation device of polymethyl methacrylate according to claim 3, characterized in that: The transmission member comprises a transmission belt and two transmission wheels. The two transmission wheels are respectively mounted on the first one-way bearing and the third stirring shaft. The transmission belt transmission connects the two transmission wheels.

5. The device for preparing polymethyl methacrylate according to claim 3, characterized in that: The top end of the first stirring shaft passes through the top end of the reactor and extends to the interior of the material preparation barrel, and is then connected to the driving sleeve through the second one-way bearing. The second agitator includes a second stirring shaft, a second stirring blade, a square sleeve and a lifting piece. The second stirring shaft is sleeved on the first stirring shaft, the square sleeve is installed on the top end of the second stirring shaft and sleeved on the driving sleeve, the second stirring blade is installed on the bottom end of the second stirring shaft, and the lifting piece is used to adjust the height of the second stirring shaft.

6. The device for preparing polymethyl methacrylate according to claim 5, characterized in that: The lifting member is a slope block, and there are two lifting members, which are symmetrically mounted at the bottom end of the second stirring shaft; The blocking device comprises a mounting shell, two push cylinders, two valve plates and two L-shaped arms. The input end of the mounting shell is connected to the liquid outlet pipe, and the output end of the mounting shell is connected to the reactor. The two push cylinders are installed on the mounting shell at intervals and are located on both sides of the liquid outlet pipe. The two valve plates are symmetrically installed inside the mounting shell. One push cylinder is connected to one valve plate through one L-shaped arm. Semicircular holes are provided on opposite sides of the two valve plates. The interior of the liquid outlet pipe is connected with a support sleeve via a connecting rod, and the support sleeve is sleeved on the second stirring shaft and is located below the second stirring blade; When the two valve plates are combined, the two valve plates are sleeved on the first stirring shaft, and the valve plates support the second stirring shaft.

7. The device for preparing polymethyl methacrylate according to claim 6, characterized in that: The tops of the opposite sides of the two valve plates and the positions corresponding to the lifting members are arranged as inclined surfaces.

8. The device for preparing polymethyl methacrylate according to claim 6, characterized in that: A cushion block is arranged at the bottom end of the second stirring blade.

9. The device for preparing polymethyl methacrylate according to claim 1, characterized in that: The polymethyl methacrylate preparation device further comprises a condenser, and an air inlet pipe and a reflux pipe of the condenser are both connected to the reaction kettle.

10. A system for preparing polymethyl methacrylate, characterized in that: The invention comprises a raw material conveying module, a preparation device for polymethyl methacrylate according to any one of claims 1 to 9, a filtering module and a drying module.

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