Three-screw deep devolatilization and extrusion double-stage unit of vaporization concentration eliminator

Abstract

The utility model discloses a three-screw deep devolatilization extrusion double-stage unit of a vaporization concentration eliminator, which comprises an upper-stage slit fin type vaporization eliminator, a gear pump and a lower-stage three-screw deep devolatilization extruder. A material discharged from the bottom of the slit fin type vaporization discharger is conveyed into a feeding hole of the three-screw deep devolatilization extruder; the slit fin type vaporization discharger comprises a tank body inner wall, a tank body outer wall and a heating medium jacket, the top of the slit fin type vaporization discharger is provided with a sizing material feeding port, and the bottom of the slit fin type vaporization discharger is provided with a sizing material discharging port and a tank body heating medium inlet; an internal heating unit heating medium inlet and an internal heating unit heating medium outlet are formed in the two sides of the top of the slit fin type vaporization ejector, and a tank body heating medium outlet and a devolatilization opening are formed in the two sides of the slit fin type vaporization ejector. The three-screw deep devolatilization extrusion two-stage unit is more efficient in the aspects of extrusion amount and residual volatile component indexes and higher in heat exchange efficiency.

Description

TECHNICAL FIELD

[0001] The utility model relates to a depth devolatilization extrusion double-stage unit, in particular to a vaporization concentration eliminator three screw rod depth devolatilization extrusion double-stage unit. BACKGROUND

[0002] In the production process of various rubber materials in the chemical adhesive industry, solution method reaction synthesis process is often used, a large amount of 40-60% solvent needs to be added as a reaction medium, and after the reaction is completed, the residual monomer, solvent, byproduct and oligomer after the reaction need to be removed again to achieve the quality standard of the adhesive product. The residual volatile content of the synthesized adhesive is often high (volatile content 40-60%), and in the past production, a single falling strip devolatilizer or double screw extruder is often used to remove the residual volatile of the adhesive.

[0003] The falling strip devolatilizer belongs to static devolatilization and has excellent heat exchange area and working volume, and is suitable for devolatilization of low viscosity rubber materials, but it cannot remove the volatile in the high viscosity rubber material (≥300Pa·S) because it does not have stirring function, and the volatile will remain in the high viscosity rubber material in the form of bubbles. The residual volatile of the general high viscosity rubber material still reaches 1%~10%, which cannot meet the requirements of high quality products. The devolatilization type double screw extruder is a dynamic devolatilization equipment, has strong self-cleaning and interface updating capacity, and can effectively remove the volatile in the rubber material, but has the following problems: the effective volume of the devolatilization type double screw extruder is limited, the residence time is short, and the heat exchange area is insufficient, so the efficiency is low, the production capacity of the single devolatilization cannot meet the production demand, and it is not suitable for directly processing the adhesive with high volatile content (viscosity ≤100Pa·S, solvent content ≥30%). SUMMARY

[0004] To solve the above problems, the utility model provides a vaporization concentration eliminator three screw rod depth devolatilization extrusion double-stage unit.

[0005] The utility model provides the following technical scheme:

[0006] In view of the defects of the above two adhesive devolatilization methods, a set of slit fin type vaporization eliminator / three screw rod depth devolatilization extrusion double-stage unit equipment is developed:

[0007] A slit fin type vaporization concentration eliminator three screw rod depth devolatilization extrusion double-stage unit adopts a double-stage structure type in series, which comprises a slit fin type vaporization eliminator, a gear pump of the upper stage and a three screw rod depth devolatilization extruder of the lower stage, the gear pump is installed below the slit fin type vaporization eliminator, the slit fin type vaporization eliminator is fed at the top, and the bottom of the slit fin type vaporization eliminator is discharged to the feeding port of the three screw rod depth devolatilization extruder.

[0008] The slit fin type vaporization discharger comprises an inner wall of a tank body, an outer wall of the tank body and a heat medium jacket located between the inner wall and the outer wall of the tank body; a rubber material feeding port is formed at the top of the slit fin type vaporization discharger, a rubber material discharging port and a tank body heat medium inlet are formed at the bottom of the slit fin type vaporization discharger, an internal heating unit heat medium inlet and an internal heating unit heat medium outlet are formed at the two sides of the top of the slit fin type vaporization discharger, and a tank body heat medium outlet and a devolatilization port are formed at the left and right sides of the slit fin type vaporization discharger.

[0009] Further, a heating unit is arranged inside the tank body of the slit fin type vaporization discharger, the heating unit comprises a heating unit heat conducting oil pipeline, an internal heating unit fin flow channel and a flow dividing cone, and the flow dividing cone is arranged inside the slit fin type vaporization discharger corresponding to the rubber material feeding port.

[0010] Further, the three-screw deep devolatilization extruder is composed of a transmission system, a barrel, a screw and a vacuum exhaust chamber, the transmission system is composed of a main motor, a shaft coupling, a transmission box and a lubricating device, the barrel is provided with a three-screw deep devolatilization extruder feeding port, the barrel is internally provided with a screw, the vacuum exhaust chamber is arranged at the upper part of the opening of the barrel, one side of the barrel is connected with the main motor through the shaft coupling, and the lubricating device is connected below the barrel.

[0011] Further, conveying elements, kneading elements and pressure building conveying elements are arranged on the screw, the conveying elements are screw structures and are used for conveying rubber materials, the kneading elements are composed of 4-7 staggered kneading blocks, the staggered angle of two adjacent kneading elements is 30-90°, and the pressure building conveying elements are single-head wide spiral rib structures and are arranged at the discharging end of the screw head.

[0012] Further, the vacuum exhaust chamber is arranged at the opening upper part of a vacuum barrel, a gas phase pipeline is arranged at the side of the vacuum exhaust chamber and is connected through a corrugated buffer pipeline and a filter, a valve and a buffer pipeline are sequentially connected at the upper part of the filter, and a condensate storage tank is connected at the lower part of the filter.

[0013] Compared with the prior art, the device has the following beneficial effects:

[0014] The complete equipment adopts double-stage devolatilization equipment in series, the upper stage is a slit fin type vaporization discharger used for primary devolatilization, most volatile components are removed, the slit fin type vaporization discharger has small volume and large heat transfer area, a heat exchange unit is arranged inside the devolatilization device, and continuous heating is provided to realize efficient devolatilization.

[0015] The lower stage is a three-screw deep devolatilization extruder used for deep devolatilization, and the three-screw deep devolatilization extruder has excellent self-cleaning, shearing and interface updating capabilities, and can remove 1-10% of volatile components remaining after devolatilization of the upper stage flash devolatilizer to below 200 ppm;

[0016] The upper and lower stage devices are connected with a vacuum condensation system, which effectively collects volatile components removed by the slit fin type vaporization discharger and the three-screw deep devolatilization extruder, and condenses the volatile components in the gas phase into liquid phase and recycles them, so that the volatile components are prevented from escaping and polluting the air. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the utility model.

[0018] Figure 2 It is a structural diagram of the slit fin type vaporization discharger.

[0019] Figure 3 It is Figure 2 It is an enlarged schematic diagram of position A.

[0020] Figure 4 It is a structural diagram of the tank body of the slit fin type vaporization discharger.

[0021] Figure 5 It is a top view of the internal heat exchange unit of the slit fin type vaporization discharger.

[0022] Figure 6 It is a structural diagram of the internal screw of the three-screw deep devolatilization extruder.

[0023] Figure 7 It is an exhaust chamber assembly diagram of the utility model.

[0024] In the figure: 1, slit fin type vaporization discharger, 2, gear pump, 3, three-screw deep devolatilization extruder, 101, rubber material feeding port, 102, internal heating unit heat medium inlet, 103, internal heating unit heat medium outlet, 104, observation sight glass, 105, rubber material discharge port, 106, internal heating unit heat conducting oil pipeline, 107, internal heating unit fin flow channel, 108, flow dividing cone, 109, tank body inner wall, 110, tank body outer wall, 111, heat medium jacket, 112, tank body heat medium inlet, 113, tank body heat medium outlet, 114, devolatilization port, 301, three-screw deep devolatilization extruder feeding port, 302, cylinder, 303, vacuum exhaust chamber, 304, filter, 305, screw, 306, corrugated buffer pipeline, 307, valve, 308, condensate storage tank, 309, conveying element, 310, kneading element, 311, pressure building conveying element, 312, main motor, 313, shaft coupling, 314, transmission box, 315, lubricating device, 316, buffer pipeline. EMBODIMENT

[0025] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the utility model.

[0026] Please refer to Figure 1 The utility model relates to a kind of slit fin type vaporization concentration eliminator three screw rod depth devolatilization extrusion double-stage unit, for volatile devolatilization treatment in adhesive material production, including slit fin type vaporization eliminator 1 of upper stage, gear pump 2 and three screw rod depth devolatilization extruder 3 of lower stage, slit fin type vaporization eliminator 1 is installed gear pump 2 below, the top feed of slit fin type vaporization eliminator 1, the bottom discharge of slit fin type vaporization eliminator 1 is sent to three screw rod depth devolatilization extruder feed port 301.

[0027] Slit fin type vaporization eliminator tank is jacketed design, adhesive entering from the feed port of slit fin type vaporization eliminator is first flattened on heated fin by flow divider cone, releases volatile under heating and vacuum, then extrudes from both sides of each layer of fin, falls into tank bottom and is discharged.Volatile is promptly extracted by vacuum condensing system through devolatilization port, while volatile in gas phase is condensed to liquid phase and collected for reuse.

[0028] Three screw rod depth devolatilization extruder belongs to dynamic equipment, for two-stage depth devolatilization link, and devolatilization efficiency is higher, the mixing of adhesive colloid, interface renewal and mass transfer and heat transfer three screw rod extruder are provided with multiple exhaust ports, and volatile is promptly extracted by vacuum condensing system.

[0029] The main body of slit fin type vaporization eliminator 1 is jacketed, and heat medium can pass between the outer wall of the tank body and the inner arm to heat and insulate the inner wall and the adhesive material.

[0030] The slit fin type vaporization eliminator 1 includes a tank body inner wall 109, a tank body outer wall 110, and a heat medium jacket 111.

[0031] The top of the slit fin type vaporization eliminator 1 is provided with an adhesive feed port 101, the bottom of the slit fin type vaporization eliminator 1 is provided with an adhesive discharge port 105 and a tank body heat medium inlet 112, the two sides of the top of the slit fin type vaporization eliminator 1 are provided with an internal heating unit heat medium inlet 102 and an internal heating unit heat medium outlet 103, and the left and right sides of the slit fin type vaporization eliminator 1 are provided with a tank body heat medium outlet 113 and a devolatilization port 114.

[0032] The tank of the slit-fin vaporizer 1 is equipped with a heating unit, which includes a heating unit heat transfer oil pipe 106, an internal heating unit finned flow channel 107 and a flow divider cone 108. The slit-fin vaporizer 1 below the rubber material inlet 101 is equipped with a flow divider cone 108. The heating unit heat transfer oil pipe 106 repeatedly zigs back and forth at a certain height, allowing the introduction of a heat medium (heat transfer oil / steam, etc.) to heat the adhesive on the finned flow channel in a timely manner, replenishing the heat consumed during the volatilization process.

[0033] The slit-fin vaporizer 1 is also equipped with observation mirrors 104 on both sides.

[0034] As attached Figure 2 As shown. The colloid entering from the colloid inlet 101 of the slit-fin vaporizer 1 is first spread out by the flow divider cone 108 onto the fins heated by the heat pipe, and flows out from the center to the periphery in each slit channel. The colloid releases volatiles under heating and vacuum conditions in the fin channels, and the volatiles are promptly removed by the vacuum condensation system through the de-evaporation port 114.

[0035] The slit channel has a multi-layered structure. If the colloid in the lower slits experiences a decrease in fluidity or stops flowing due to a drop in temperature during the devolatilization process, the remaining colloid will be squeezed out from the upper or multiple slit channels. The colloid that has accumulated in the lower layer due to loss of self-flowability caused by the drop in temperature is continuously heated by the heat pipes in the finned channel, restoring its fluidity and allowing it to continue flowing outwards to downstream equipment. This multi-layered channel and continuous heating structure design allows for automatic flow distribution and heat replenishment of the colloid, preventing clogging of the channels and ensuring continued equipment operation.

[0036] The rubber compound is discharged through the rubber compound discharge port 105 of the slit fin vaporizer by gravity and subsequent colloid thrust, and is introduced into the next stage three-screw deep devolatilization extruder 3 by gear pump 2, thus achieving primary devolatilization.

[0037] Slit-fin vaporizer parameters:

[0038] 1. Slit-fin vaporizer with a heat exchange area of ​​0.5-10㎡;

[0039] 2. The tank design temperature is <300℃ and the design pressure is ≤3MPa;

[0040] 3. The number of slit channels in the internal heating unit is 10-50 layers.

[0041] Figure 1As shown, the three-screw deep devolatilization extruder 3 is composed of a transmission system, a barrel 302, a screw 305, and a vacuum exhaust chamber 303, and the transmission system is composed of a main motor 312, a shaft coupling 313, a transmission box 314, and a lubricating device 315. There are 1-10 groups of exhaust chamber 303 components.

[0042] The barrel of the three-screw deep devolatilization extruder 3 is composed of 6-15 barrel sections connected in series, and each connection of the barrel sections is equipped with a sealing device. The first section of the side feeding barrel is connected with the outlet of the lower gear pump 2 of the upstream slit fin vaporization discharger 1, and the full-closed barrel 2-10 sections are connected. Each barrel section is provided with a cooling water channel and is connected with an internal circulating cooling water device for cooling the internal temperature of the rubber material.

[0043] The barrel 302 is provided with a three-screw deep devolatilization extruder feeding port 301, and the barrel 302 is provided with a screw 305. The vacuum exhaust chamber 303 is arranged at the upper part of the opening of the barrel 302. The three screws are arranged in a horizontal line, and there is an additional meshing area compared with a double-screw extruder, so that the mixing and interface updating effect of the screw on the rubber material is better. The screws are meshed with each other, so they have excellent self-cleaning and interface updating capabilities, and during operation, the rubber material is continuously and smoothly pushed forward through the rotation of the threads.

[0044] One side of the barrel 302 is connected with the main motor 312 through the transmission box 314 and the shaft coupling 313, and the lower part of the barrel 302 is connected with the lubricating device 315.

[0045] The screw 305 is provided with a conveying element 309, a kneading element 310, and a pressure building conveying element 311. The conveying element 309 is a threaded structure and serves to convey the rubber material. The kneading element 310 is composed of 4-7 staggered kneading blocks, and the staggered angle of the two adjacent kneading elements is 30-90°. The kneading element 310 mainly stirs and shears the rubber material, so that the volatile components inside the rubber material are updated to the outside and are immediately removed by the vacuum condensing system. The kneading element 310 is usually used in series with 2-10 pieces (3 pieces in series in the drawing), forming a group of kneading and mixing areas to improve the mixing and interface updating effect on the raw materials. The pressure building conveying element 311 is a single-head wide spiral rib structure, which can effectively prevent the backflow of the rubber liquid through the gap between the spiral rib and the barrel, and has stronger pressure building and conveying capacity, and is usually arranged at the discharge end of the screw head.

[0046] The gas phase pipeline outside the vacuum exhaust chamber 303 is connected with a vacuum condensing device.

[0047] Vacuum exhaust chamber 303 is installed on the upper part of the opening of the vacuum cylinder, and the side of the vacuum exhaust chamber 303 is provided with a gas phase pipeline and is connected through a corrugated buffer pipeline 306 and a filter 304. The upper part of the filter 304 is sequentially connected with a valve 307, a buffer pipeline 316, and finally connected with a pipeline of a vacuum condensing system. The lower part of the filter 304 is connected with a condensate storage tank 308 for collecting the volatile liquid condensed and falling back in the pipeline.

[0048] The corrugated buffer pipeline 306 is used for transition connection between hard pipes and compensates the deformation caused by thermal stress between pipes. The valve 307 is used for controlling the opening and closing of the gas phase passage of the pipeline and is used for operation during maintenance or start-stop of the machine. The filter 304 is internally provided with a filter screen for blocking the rubber material carried out by air suction and preventing the rubber material from entering the vacuum condensing system.

[0049] Three-screw deep devolatilization extruder equipment parameters:

[0050] 1. Screw diameter D: 25-330mm;

[0051] 2. Length-diameter ratio of screw L / D: 20-68:1;

[0052] 3. Screw speed: 30-330rpm;

[0053] 4. Exhaust chamber number: 1-10 groups.

[0054] The vacuum condensing system is composed of a vacuum pump, a pre-pump cooler, a condensate storage tank, a pipeline and a valve and is used for extracting the volatiles removed in the slit fin type vaporization discharger 1 and the three-screw deep devolatilization extruder 3 and condensing and collecting the volatiles.

[0055] The slit fin type vaporization discharger and the deep devolatilization extrusion equipment adopt a double-stage structure type in series connection and comprise: the slit fin type vaporization discharger of the upper stage, the gear pump, the three-screw deep devolatilization extruder of the lower stage and the matched vacuum condensing system.

[0056] The slit fin type vaporization discharger is designed in a jacket type and is divided into a tank body and an internal heating unit. The tank body is provided with a feeding port and a discharging port, 1-2 devolatilization exhaust ports, 1-3 observation windows, 1-2 tank body heat medium inlets and outlets and 1-2 internal heating unit heat medium inlets and outlets. The design pressure of the tank body is <3MPa and the design temperature is <300 DEG C. The design pressure of the jacket is <5MPa and the design temperature is <300 DEG C. The internal heating unit is composed of multiple groups of horizontal fin flow channels and vertical heat conduction pipelines, and the fin flow channel layer number is 10-50 layers.

[0057] The three-screw deep devolatilization extruder comprises a transmission system, a barrel, a screw, and a vacuum exhaust chamber assembly. The screw diameter of the three-screw deep devolatilization extruder is 25-330 mm, the length-diameter ratio of the screw is 20-68:1, the screw rotation speed is 30-330 rpm, and the exhaust chamber has 1-10 groups. The screw element is mainly composed of a conveying element, a kneading element, and a pressure-building conveying element. The conveying element is a threaded structure and serves to convey the rubber compound. The kneading element is composed of 4-7 staggered kneading blocks, and the staggered angle of adjacent two kneading elements is 30-90°.

[0058] 1. The complete device is suitable for removing high solvent content of adhesives. The devolatilization equipment adopts a double-stage type corresponding to different solvent contents and viscosities of the material state in the initial and later stages of devolatilization operation. The upper-stage slit fin type vaporization discharger is used for the initial high solvent content (≥40%) and low viscosity material (≤10 Pa·S) working condition, and the lower-stage three-screw deep devolatilization extruder is used for the later high viscosity (≥300 Pa·S) state. Continuous operation can be performed, and compared with the previous use of a falling strip devolatilizer or a twin-screw extruder, it is more efficient in terms of extrusion amount and residual volatile fraction indicators.

[0059] 2. The upper-stage slit fin type vaporization discharger is a static devolatilization equipment with large working volume and large heat exchange area. The slit fin type vaporization discharger has a higher heat exchange efficiency than the conventional falling strip devolatilizer due to the use of a slit fin type heating structure inside.

[0060] 3. The upper-stage slit fin type vaporization discharger tank is designed with a jacket and is heated by a heat medium to keep the tank warm. The tank is provided with an internal heating unit composed of a tube type heat exchanger and a slit fin type rubber flow channel, which can supplement the heat consumed in the preliminary devolatilization process in time to prevent the flow channel from being blocked due to the reduction of the adhesive temperature and improve the devolatilization effect at this stage, thereby further reducing the volatile fraction content of the adhesive rubber compound at the outlet section.

[0061] 4. The lower-stage three-screw deep devolatilization extruder adopts a horizontal arrangement of three screws. Compared with the common double-screw extruder of the same specification, it has about 50% more working volume and one more set of meshing area. The additional 50% working volume can increase the gas phase space during devolatilization and exhaust, thereby improving the extrusion amount. The additional one set of meshing area can better mix, update the interface, and transfer mass and heat for the adhesive rubber compound. Meanwhile, the additional screw also increases the working volume and the cross-sectional area of the gas phase opening, thereby improving the deep devolatilization efficiency. As a secondary deep devolatilization link, it can reduce the volatile fraction content to below 200 ppm.

[0062] This set of devolatilization equipment is suitable for removing residual volatile fractions of various adhesives and is also applicable to other high molecular materials such as resins, elastomers, and rubbers.

[0063] Although the embodiments of the present application have been shown and described, it is to be understood that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A two-stage two-screw deep devouring extrusion unit with a vaporization concentration removal device, characterized in that: The structure is composed of two stages connected in series, including an upper stage slit-fin vaporizer (1), a gear pump (2), and a lower stage three-screw deep devouring extruder (3). The gear pump (2) is installed below the slit-fin vaporizer (1). The top of the slit-fin vaporizer (1) is fed and the bottom of the slit-fin vaporizer (1) is discharged into the feed port (301) of the three-screw deep devouring extruder. The slit-fin vaporizer (1) includes an inner wall (109) of the tank, an outer wall (110) of the tank, and a heat medium jacket (111). The heat medium jacket (111) is located between the inner wall (109) of the tank and the outer wall (110) of the tank. The top of the slit-fin vaporizer (1) has a rubber material inlet (101), the bottom of the slit-fin vaporizer (1) has a rubber material discharge port (105) and a tank heat medium inlet (112), the top two sides of the slit-fin vaporizer (1) have an internal heating unit heat medium inlet (102) and an internal heating unit heat medium outlet (103), and the left and right sides of the slit-fin vaporizer (1) have a tank heat medium outlet (113) and a volatilization port (114).

2. The two-stage deep devouring extrusion unit with a vaporization concentration remover according to claim 1, characterized in that: The tank of the slit-fin vaporizer (1) is equipped with a heating unit. The heating unit includes a heating unit heat transfer oil pipe (106), an internal heating unit fin flow channel (107), and a flow divider cone (108). The slit-fin vaporizer (1) below the rubber material inlet (101) is equipped with a flow divider cone (108).

3. The two-stage deep devouring extrusion unit with a vaporization concentration remover according to claim 1, characterized in that: The three-screw deep devouring extruder (3) consists of a transmission system, a barrel (302), a screw (305), and a vacuum exhaust chamber (303). The transmission system consists of a main motor (312), a coupling (313), a transmission box (314), and a lubrication device (315). The barrel (302) has a feed port (301) for the three-screw deep devouring extruder. The screw (305) is inside the barrel (302). The vacuum exhaust chamber (303) is located at the top of the opening of the barrel (302). One side of the barrel (302) is connected to the main motor (312) through the transmission box (314) and the coupling (313). The lubrication device (315) is connected to the bottom of the barrel (302).

4. The two-stage deep devolatilization extrusion unit with a vaporization concentration remover according to claim 1, characterized in that: The screw (305) is equipped with a conveying element (309), a kneading element (310), and a pressure-building conveying element (311). The conveying element (309) has a threaded structure and is used to convey colloidal materials. The kneading element (310) consists of 4-7 staggered kneading blocks, with the staggered angle between two adjacent kneading elements being 30-90°. The pressure-building conveying element (311) has a single-head wide-ribbed structure and is arranged at the discharge end of the screw head.

5. The two-stage deep devolatilization extrusion unit with a vaporization concentration remover according to claim 3, characterized in that: The vacuum exhaust chamber (303) is installed on the upper part of the opening of the vacuum cylinder. The side of the vacuum exhaust chamber (303) is provided with a gas phase pipe and is connected to the filter (304) through a corrugated buffer pipe (306). The upper part of the filter (304) is connected to a valve (307) and a buffer pipe (316) in sequence, and the lower part of the filter (304) is connected to a condensate storage tank (308).

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