Horizontal polycondensation devolatilization reactor

Abstract

The utility model discloses a horizontal polycondensation and devolatilization reactor which comprises a horizontal barrel, a melt feed port is arranged at the bottom of one end of the barrel, a melt discharge port is arranged at the bottom of the other end of the barrel, and a middle partition plate is arranged in the middle of the barrel to divide an inner cavity of the barrel into a polycondensation cavity and a devolatilization cavity. An outlet in the bottom of the discharging end of the polycondensation cavity is connected with an inlet in the bottom of the feeding end of the devolatilization cavity through a U-shaped connecting pipe, and a liquid level adjusting valve is mounted at the middle section of the U-shaped connecting pipe; gas phase outlets are respectively formed in the tops of the polycondensation cavity and the devolatilization cavity, stirring shafts are respectively arranged along the axes of the polycondensation cavity and the devolatilization cavity, stirring blades are respectively arranged on the stirring shafts, and catalyst beds are respectively arranged in the middle sections of the polycondensation cavity and the devolatilization cavity. A plurality of heating partition plates are arranged on the bottom wall of the devolatilization cavity, overflowing holes are formed in the lower portion of each heating partition plate, and the overflowing holes of the adjacent heating partition plates are arranged in a staggered mode. According to the horizontal polycondensation devolatilization reactor, the content of monomers in PA6 melt can be reduced to 0.5% or below, and the requirement for direct spinning of the PA6 melt is met.

Description

Technical Field

[0001] The utility model relates to a polymerization reactor, in particular to a horizontal polycondensation devolatilization reactor, belonging to the technical field of polyester production equipment. Background Art

[0002] The PA6 polymerization device is used to increase the viscosity of PA6 and remove monomers from the PA6 melt, reducing the monomer content (oligomers, CPL monomers, etc.) in the conventional PA6 melt from the current 8%~10% to below 0.5%, which can meet the requirements of direct melt spinning or direct film drawing.

[0003] The existing process uses a two-step method to carry out polycondensation reaction. The melt after the reaction is pelletized and then sent to the subsequent extraction tower to extract the monomers in the slices. Finally, it is sent to a drying tower for drying. Finally, the finished product is packaged and sold.

[0004] Using traditional vertical reactors, it is impossible to reduce the monomer content in the PA6 melt from 8%~10% to below 0.5%. This is mainly because through normal pressure polymerization reaction, there are always about 8%~10% monomers in the PA6 melt. If these monomers are not removed, they will seriously affect downstream processing (such as spinning, film drawing or engineering plastics, etc.). Conventionally, the monomers are extracted through the extraction mechanism and then the slices are dried. Utility Model Content

[0005] The purpose of this section is to summarize some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract and utility model title of this application, and such simplifications or omissions shall not be used to limit the scope of the present invention.

[0006] In view of the above problems and / or the problems existing in the prior art, the present utility model is proposed.

[0007] The purpose of the utility model is to overcome the problems existing in the prior art and provide a horizontal polycondensation devolatilization reactor, which can reduce the monomer content in the PA6 melt to below 0.5% and meet the requirements of PA6 melt direct spinning.

[0008] In order to solve the above technical problems, the utility model provides a horizontal polycondensation and devolatilization reactor, comprising a horizontal cylinder, a melt feed port being provided at the bottom of one end of the cylinder, and a melt discharge port being provided at the bottom of the other end of the cylinder, a middle partition being provided in the middle of the cylinder to divide the inner cavity of the cylinder into a polycondensation chamber and a devolatilization chamber, the bottom outlet of the discharge end of the polycondensation chamber is connected to the bottom inlet of the feed end of the devolatilization chamber through a U-shaped connecting pipe, and a liquid level regulating valve is installed in the middle section of the U-shaped connecting pipe; gas phase outlets are respectively provided at the tops of the polycondensation chamber and the devolatilization chamber, stirring shafts are respectively provided along the axes of the polycondensation chamber and the devolatilization chamber, stirring blades are respectively provided on the stirring shafts, and catalyst beds are respectively provided in the middle sections of the polycondensation chamber and the devolatilization chamber.

[0009] As an improvement of the present invention, the bottom wall of the devolatilization chamber is provided with a plurality of heating partitions along the melt flow direction.

[0010] As a further improvement of the present invention, a flow hole is provided at the bottom of each heating baffle, and the flow holes of adjacent heating baffles are arranged in a staggered manner.

[0011] As a further improvement of the present invention, the top of each heating baffle is lower than the axis of the cylinder, and each heating baffle is provided with a notch on both sides and a drain hole at the center of the bottom.

[0012] As a further improvement of the present invention, each heating baffle is respectively provided with a heat medium heating channel.

[0013] As a further improvement of the present invention, the catalyst bed is provided with metal catalyst coils made of a variety of metal kneading catalysts, and a heat medium inlet and a heat medium outlet are provided at both ends of the metal catalyst coils.

[0014] As a further improvement of the present invention, the metal catalyst pipes are provided with multiple groups connected in parallel, and each group is coiled in an S shape.

[0015] As a further improvement of the present invention, the height of the catalyst bed in the polycondensation chamber is greater than the height of the catalyst bed in the devolatilization chamber.

[0016] As a further improvement of the present invention, the distribution density of the stirring blades in the polycondensation chamber is higher than the distribution density of the stirring blades in the devolatilization chamber.

[0017] As a further improvement of the present invention, manholes are respectively provided on the tops of the polycondensation chamber and the devolatilization chamber, and the manholes are respectively located directly above the catalyst bed.

[0018] As a further improvement of the present invention, the peripheries of the polycondensation chamber and the devolatilization chamber are respectively provided with heating jackets, and both ends of the polycondensation chamber and the devolatilization chamber are respectively provided with liquid level gauges and thermometers.

[0019] As a further improvement of the present invention, the inner ends of the stirring shafts of the condensation chamber and the devolatilization chamber are respectively supported on the middle partition and are respectively provided with shaft seals. The outer ends of the stirring shafts of the condensation chamber and the devolatilization chamber respectively extend from the center of the corresponding heads and are respectively connected to the output ends of the corresponding reducers. The input ends of the two reducers are respectively driven by corresponding stirring motors.

[0020] Compared with the existing technology, the utility model has achieved the following beneficial effects: 1. It can reduce the monomer content in the PA6 melt to below 0.5%, realize direct spinning or direct film drawing of the PA6 melt, and can reduce or directly eliminate the equipment of the extraction system and slice drying system in the original PA6 polymerization device, thereby reducing equipment investment;

[0021] 2. Compared with the traditional process, PA6 melt no longer needs extraction, drying, cooling and subsequent reheating, which greatly reduces operating costs. The processing cost of PA6 slices per ton is expected to be reduced by 800 yuan / ton to 1000 yuan / ton;

[0022] 3. Due to the cancellation of the extraction system and drying system, the floor space of the device can be greatly reduced, and the civil engineering investment can be reduced;

[0023] 4. Since the extraction system and drying system are cancelled, the discharge of sewage can be greatly reduced, the treatment load of sewage equipment can be reduced, and the interference to the environment can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work. The drawings are only provided for reference and explanation, and are not intended to limit the present invention. Among them:

[0025] Figure 1 This is a schematic structural diagram of the horizontal polycondensation devolatilization reactor of the utility model;

[0026] Figure 2 for Figure 1 Schematic diagram of the heating partition in the AA section;

[0027] Figure 3 for Figure 1 Schematic diagram of the heating baffle in the middle BB section;

[0028] In the figure: 1. Cylinder; 1a. Condensation chamber; 1a1. Melt feed port; 1a2. Condensation chamber gas phase outlet; 1a3. Condensation chamber manhole; 1b. Devolatilization chamber; 1b1. Melt discharge port; 1b2. Devolatilization chamber gas phase outlet; 1b3. Devolatilization chamber manhole; 1c. Middle partition; 2. U-shaped connecting pipe; 3. Liquid level regulating valve; 4. Condensation chamber stirring motor; 5. Condensation chamber reducer; 6. Condensation chamber stirring shaft; 6a. Condensation chamber stirring blade; 7. Condensation chamber catalyst bed; 8. Devolatilization chamber stirring motor; 9. Devolatilization chamber reducer; 10. Devolatilization chamber stirring shaft; 10a. Devolatilization chamber stirring blade; 11. Devolatilization chamber catalyst bed; 12. Heating partition; 12a. Flow hole; 12b. Drain hole; 13. Thermometer; 14. Liquid level gauge; 15. Heating jacket. DETAILED DESCRIPTION

[0029] In the following description of the present invention, the terms "upper", "lower", "front", "back", "left", "right", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not mean that the device must have a specific direction.

[0030] In order to make the technical means, creative features, objectives and effects of the present invention easier to understand, the present invention is further described below with reference to specific figures. Obviously, the embodiments described are only a part of the present invention, not all of the embodiments.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0032] like Figures 1 to 3 As shown, the horizontal polycondensation and devolatilization reactor of the present invention comprises a horizontal cylinder 1. A central partition 1c is provided in the middle of the cylinder 1, dividing the cylinder inner cavity into relatively independent polycondensation chambers 1a and 1b. The outer peripheries of the polycondensation chambers 1a and 1b are respectively provided with heating jackets 15. The bottom of the feed end of the polycondensation chamber 1a is provided with a melt feed port 1a1, and the bottom of the discharge end of the devolatilization chamber 1b is provided with a melt discharge port 1b1. The bottom outlet of the discharge end of the polycondensation chamber 1a is connected to the bottom inlet of the feed end of the devolatilization chamber 1b via a U-shaped connecting pipe 2. A liquid level regulating valve is installed in the middle section of the U-shaped connecting pipe 2. The top of the polycondensation chamber 1a is provided with a polycondensation chamber gas phase outlet 1a2, and the top of the devolatilization chamber 1b is provided with a devolatilization chamber gas phase outlet 1b2. The ends of the polycondensation chamber 1a and the devolatilization chamber 1b are respectively provided with a liquid level gauge 14 and a thermometer 13 for measuring the liquid level and temperature in and out of the chambers.

[0033] A polycondensation chamber stirring shaft 6 is provided along the axis of the polycondensation chamber 1a, and a polycondensation chamber stirring blade 6a is provided on the polycondensation chamber stirring shaft 6; a devolatilization chamber stirring shaft 10 is provided along the axis of the devolatilization chamber 1b, and a devolatilization chamber stirring blade 10a is provided on the devolatilization chamber stirring shaft 10. The polycondensation chamber stirring shaft 6 and the devolatilization chamber stirring shaft 10 are coaxial, and the inner ends of the polycondensation chamber stirring shaft 6 and the devolatilization chamber stirring shaft 10 are opposite and respectively supported on the middle partition 1c. The outer ends of the polycondensation chamber stirring shaft 6 and the devolatilization chamber stirring shaft 10 respectively extend from the center of the corresponding head, and the polycondensation chamber stirring shaft 6 and the devolatilization chamber stirring shaft 10 are respectively provided with shaft seals at the locations where they pass through the head and the center of the middle partition.

[0034] The melt viscosity in the polycondensation chamber 1a is lower than that in the devolatilization chamber 1b, and the distribution density of the stirring blades 6a in the polycondensation chamber is higher than that of the stirring blades 10a in the devolatilization chamber.

[0035] The outer end of the condensation chamber stirring shaft 6 is connected to the output end of the condensation chamber reducer 5, and the input end of the condensation chamber reducer 5 is driven by the condensation chamber stirring motor 4; the outer end of the devolatilization chamber stirring shaft 10 is connected to the output end of the devolatilization chamber reducer 9, and the input end of the devolatilization chamber reducer 9 is driven by the devolatilization chamber stirring motor 8.

[0036] The polycondensation chamber stirring motor 4 drives the polycondensation chamber stirring shaft 6 to rotate after being decelerated by the polycondensation chamber reducer 5, and the devolatilization chamber stirring motor 8 drives the devolatilization chamber stirring shaft 10 to rotate after being decelerated by the devolatilization chamber reducer 9. The speeds of the polycondensation chamber stirring shaft 6 and the devolatilization chamber stirring shaft 10 can be controlled separately according to the needs of the process.

[0037] A condensation chamber catalyst bed 7 is provided in the middle section of the condensation chamber 1a, and a devolatilization chamber catalyst bed 11 is provided in the middle section of the devolatilization chamber 1b. The liquid level in the condensation chamber 1a is higher than the liquid level in the devolatilization chamber 1b, and the height of the catalyst bed in the condensation chamber 1a is greater than the height of the catalyst bed in the devolatilization chamber 1b.

[0038] The catalyst bed is equipped with metal catalyst coils made from a combination of various metal catalysts, including platinum, nickel, titanium, antimony, and trace elements. These coils are coiled in an S-shape, with a heat medium inlet and outlet at each end. The interior of the coils is heated with thermal oil, hydrogenated terphenyl, or other heat transfer media. To improve reaction efficiency, multiple sets of metal catalyst coils can be installed in parallel, each coiled in an S-shape.

[0039] A material control valve is installed at the inlet of the horizontal reactor. The melt after the polycondensation reaction enters the polycondensation chamber 1a from the melt feed port 1a1 through the melt pump or the action of the potential difference. The operating temperature in the polycondensation chamber 1a is: 220℃~280℃, and the working pressure is: 10kPa(G)~500kPa(G).

[0040] Driven by the polycondensation chamber's stirring shaft 6 and its paddles 6a, the melt passes through the polycondensation chamber's catalyst bed 7, promoting further polymerization of the PA6 in the forward direction. The melt then enters the devolatilization chamber 1b through the U-shaped connecting pipe 2 and the liquid level control valve 3. The liquid level in the polycondensation chamber 1a is regulated by adjusting the opening of the liquid level control valve 3. The operating temperature in the devolatilization chamber 1b is 220°C to 280°C, and the operating pressure is 10 Pa(A) to 200 kPa(G). Driven by the devolatilization chamber's stirring shaft 10 and its paddles 10a, the melt passes through the devolatilization chamber's catalyst bed 11, promoting further polymerization of the PA6 in the forward direction.

[0041] The combined effects of temperature, pressure, agitation, and the catalyst bed remove monomer from the PA6 melt, reducing the monomer content from the current 8%-10% to below 0.5%. The extent to which the various metal kneading catalysts participate in the PA6 polymerization reaction depends on the surface temperature of the metal catalyst coil. When the monomer content of the PA6 melt at melt outlet 1b1 exceeds 0.5%, the temperature of the thermal oil is increased, raising the surface temperature of the metal catalyst coil to reduce the monomer content in the PA6 melt.

[0042] The top of the polycondensation chamber 1a is equipped with a polycondensation chamber manhole 1a3, located directly above the polycondensation chamber catalyst bed 7. The top of the devolatilization chamber 1b is equipped with a devolatilization chamber manhole 1b3, located directly above the devolatilization chamber catalyst bed 11. When the catalyst surface temperature exceeds the melt temperature by more than 35-40°C and the monomer content in the melt fails to decrease, indicating that the catalyst has failed, a new catalyst tube can be replaced through the polycondensation chamber manhole 1a3 or the devolatilization chamber manhole 1b3.

[0043] The bottom wall of the devolatilization chamber 1b is provided with multiple heating baffles 12 along the melt flow direction to facilitate full contact and heating of the material with the heating baffles 12. The purpose is to facilitate the escape of monomers in the PA6 melt in the system under the action of temperature. Each heating baffle 12 is respectively provided with a heat medium heating channel to facilitate the introduction of heat medium and control of the heating temperature. The number of heating baffles 12 is set according to the production capacity.

[0044] Each heating baffle 12 is provided with a flow hole 12a at its lower portion. The flow holes 12a of adjacent heating baffles 12 are staggered, allowing the PA6 melt to flow in an S-shaped pattern as it passes through each heating baffle 12 in the devolatilization chamber 1b. The top of each heating baffle 12 is lower than the cylinder axis, and each heating baffle 12 has a notch on either side. A drain hole 12b is provided at the center of the bottom of each heating baffle 12 to prevent melt residue and facilitate future internal cleaning.

[0045] The monomer removed from the melt is carried out through the vapor phase outlet 1a2 of the polycondensation chamber and the vapor phase outlet 1b2 of the devolatilization chamber at the top of the reactor under the action of vacuum and fed into a collector for collection. PA6 melt with a content below 0.5% is transported by a melt pump directly to the spinning workshop or film drawing for immediate use.

[0046] The above description is only a preferred embodiment of the present invention, which shows and describes the basic principles, main features and advantages of the present invention, but does not limit the scope of patent protection of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. In addition to the above embodiments, the present invention may have other implementation methods without departing from the spirit and scope of the present invention. The present invention may also have various changes and improvements, and all technical solutions formed by equivalent replacement or equivalent transformation fall within the scope of protection required by the present invention. The scope of protection required by the present invention is defined by the attached claims and their equivalents. Technical features not described in the present invention can be achieved by or using existing technologies, and will not be described here.

Claims

1. A horizontal polycondensation devolatilization reactor comprising a horizontal cylinder, a melt feed port being provided at the bottom of one end of the cylinder, and a melt discharge port being provided at the bottom of the other end of the cylinder, characterized in that: A middle partition is provided in the middle of the cylinder to divide the inner cavity of the cylinder into a condensation chamber and a devolatilization chamber. The bottom outlet of the discharge end of the condensation chamber is connected to the bottom inlet of the feed end of the devolatilization chamber through a U-shaped connecting pipe. The middle section of the U-shaped connecting pipe is equipped with a liquid level regulating valve; the tops of the condensation chamber and the devolatilization chamber are respectively provided with gas phase outlets, and stirring shafts are respectively provided along the axes of the condensation chamber and the devolatilization chamber, and stirring blades are respectively provided on the stirring shafts. Catalyst beds are respectively provided in the middle sections of the condensation chamber and the devolatilization chamber.

2. The horizontal polycondensation devolatilization reactor according to claim 1, wherein: The bottom wall of the devolatilization chamber is provided with a plurality of heating partitions along the melt flow direction.

3. The horizontal polycondensation devolatilization reactor according to claim 2, wherein: The lower part of each heating baffle is respectively provided with a flow hole, and the flow holes of adjacent heating baffles are staggered.

4. The horizontal polycondensation devolatilization reactor according to claim 3, wherein: The top of each heating baffle is lower than the axis of the cylinder, and each heating baffle is provided with notches on both sides and a drainage hole at the center of the bottom.

5. The horizontal polycondensation devolatilization reactor according to claim 2, characterized in that: Each heating baffle is respectively provided with a heat medium heating channel.

6. The horizontal polycondensation devolatilization reactor according to claim 1, characterized in that: The catalyst beds are respectively provided with metal catalyst coils made of a variety of metal kneading catalysts, and both ends of the metal catalyst coils are respectively provided with a heat medium inlet and a heat medium outlet.

7. The horizontal polycondensation devolatilization reactor according to claim 6, characterized in that: The metal catalyst pipelines are provided with multiple groups connected in parallel, and each group is coiled in an S shape.

8. The horizontal polycondensation devolatilization reactor according to claim 1, characterized in that: The height of the catalyst bed in the polycondensation chamber is greater than the height of the catalyst bed in the devolatilization chamber.

9. The horizontal polycondensation devolatilization reactor according to claim 1, characterized in that: The distribution density of the stirring blades in the polycondensation chamber is higher than that in the devolatilization chamber.

10. The horizontal polycondensation devolatilization reactor according to claim 1, characterized in that: The tops of the polycondensation chamber and the devolatilization chamber are respectively provided with manholes, and the manholes are respectively located directly above the catalyst beds.

11. The horizontal polycondensation devolatilization reactor according to claim 1, characterized in that: The peripheries of the polycondensation chamber and the devolatilization chamber are respectively provided with heating jackets, and both ends of the polycondensation chamber and the devolatilization chamber are respectively provided with liquid level gauges and thermometers.

12. The horizontal polycondensation devolatilization reactor according to any one of claims 1 to 11, characterized in that: The inner ends of the stirring shafts of the condensation chamber and the devolatilization chamber are respectively supported on the middle partition and are respectively provided with shaft seals. The outer ends of the stirring shafts of the condensation chamber and the devolatilization chamber respectively extend from the center of the corresponding heads and are respectively connected to the output ends of the corresponding reducers. The input ends of the two reducers are respectively driven by corresponding stirring motors.

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