Recycling cracker for polyamide 6 slice production

Abstract

The utility model relates to the technical field of crackers, and provides a recycling cracker for polyamide 6 slice production, the recycling cracker comprises a cracker body, a feeding pipe is arranged at the bottom of the cracker body, a discharging pipe is arranged at the top of the cracker body, at least one flow dividing pattern plate is arranged in the cracker body, and a plurality of flow dividing holes are formed in the flow dividing pattern plate. The split-flow pattern plate is arranged in the cracker body, so that a concentrated solution material entering the cracker body forms a plug flow with a balanced flow rate after passing through the split-flow pattern plate, the reaction time is prolonged, and sufficient reaction is ensured; through the arrangement of the pressure control valve and the pressure gauge, the working pressure in the cracker body can be higher than the pressure of saturated water vapor at the process temperature, the tank can be closed without dehydration while sufficient reaction time is ensured, a complex steam discharge and condensation system in the prior art is abandoned, and the energy consumption is reduced. And the stable quality of the product after the cracked concentrated solution enters the polymerization kettle for reaction is ensured.

Description

Technical Field

[0001] The present application belongs to the technical field of crackers, and more specifically, relates to a recycling cracker for the production of polyamide 6 chips. Background Art

[0002] Domestic large-scale polymerization production equipment basically adopts hydrolysis ring-opening polymerization. After the reaction is completed, the sliced ​​particles contain about 10% of small molecular substances. The sliced ​​particles are extracted with water, and the extracted liquid containing small molecular substances is concentrated by triple-effect evaporation. The concentrated liquid then enters the cracking reactor and enters the entire polymerization system for reuse after cracking.

[0003] For example, Chinese patent CN203768272U discloses a recovery cracker for the production of nylon 6 chips, including a cracker body and a caprolactam storage tank. The function of the recovery cracker is to ensure the normal operation of the cracker in the event of a filter failure. The flow rate is maintained stable through a rehydration valve and a rehydration pump. A constant temperature tank and an external filtration device are optional to further improve the stability and efficiency of the system. However, the cracker body it adopts is still a conventional structure, including a feed pipe and a discharge pipe. The material flows rapidly inside it, resulting in a short cracking reaction time of the cracker in the existing production process, insufficient reaction, and a small amount of oligomers enriched in the polymerization system, causing fluctuations in the production process. In severe cases, it can also cause shutdown. Therefore, it is urgent to solve the problem of incomplete cracking reaction of the cracker. Utility Model Content

[0004] In response to the technical problems of short cracking reaction time and insufficient reaction in the cracker in the prior art, the purpose of the embodiment of the present application is to provide a recovery cracker for the production of polyamide 6 chips, by adding a flower plate that acts as a diversion to reduce the material flow rate and maintain the flat flow of the material, thereby extending the cracking reaction time and making the reaction more complete.

[0005] To achieve the above-mentioned purpose, the technical solution adopted in this application is: to provide a recycling cracker for the production of polyamide 6 chips, including a cracker body, a feed pipe is provided at the bottom of the cracker body, a discharge pipe is provided at the top, and at least one diversion plate is provided in the cracker body, and a plurality of diversion holes are provided on the diversion plate.

[0006] In one embodiment, the discharge pipe is provided with a pressure control valve and a pressure gauge.

[0007] In one embodiment, an observation hole is provided on the cracker body.

[0008] In one embodiment, the cracker body comprises an upper tank body and a lower tank body, wherein the upper tank body and the lower tank body are sealed and butted against each other and connected by a circle of bolts arranged at intervals.

[0009] In one embodiment, the outer sides of the upper tank body and the lower tank body are both provided with insulation jackets.

[0010] In one embodiment, the feed pipe is connected to a serpentine heater.

[0011] In one embodiment, the pore size of the diversion hole is ≥1 mm.

[0012] In one embodiment, the cracker body has a height to diameter ratio of ≥3.

[0013] The beneficial effects of the recovery cracker for polyamide 6 chip production provided in the present application are: by arranging a diverter plate in the cracker body, it is ensured that the concentrated liquid material entering forms a plug flow with a balanced flow rate after passing through the diverter plate, which not only extends the reaction time but also ensures sufficient reaction; by arranging a pressure control valve and a pressure gauge, the working pressure in the cracker body can be made higher than the saturated water vapor pressure at the process temperature, while ensuring sufficient reaction time, the tank can be sealed without dehydration, and the complex steam discharge and condensation system in the prior art is discarded, ensuring that the quality of the product after the concentrated liquid after cracking enters the polymerization kettle for reaction is stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0015] Figure 1 A schematic plan view of the structure of a recycling cracker for producing polyamide 6 chips provided in an embodiment of the present application;

[0016] Figure 2 A schematic diagram of the top view of the flat plate structure of the diversion plate in the recovery cracker for the production of polyamide 6 chips provided in an embodiment of the present application.

[0017] Among them, the reference numerals in the figures are:

[0018] 1. Cracker body; 11. Upper tank body; 12. Lower tank body; 13. Bolts; 14. Insulation jacket; 2. Feed pipe; 3. Discharge pipe; 4. Diverter plate; 41. Diverter hole; 5. Observation hole; 6. Thermometer. DETAILED DESCRIPTION

[0019] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clearly understood, this application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0020] It should be noted that when an element is referred to as being “fixed on” or “disposed on” another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being “connected to” another element, it may be directly connected to the other element or indirectly connected to the other element.

[0021] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0022] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0023] like Figure 1 and Figure 2 As shown, a recycling cracker for the production of polyamide 6 chips provided in an embodiment of the present application is now described. The recycling cracker for the production of polyamide 6 chips includes a cracker body 1, a feed pipe 2 is provided at the bottom of the cracker body 1, a discharge pipe 3 is provided at the top, and an observation hole 5 is also provided on the cracker body 1 for observing the internal situation. Among them, at least one diversion plate 4 is provided in the cracker body 1, and a plurality of diversion holes 41 are provided on the diversion plate 4. The diversion holes 41 realize the diversion of the internal concentrated liquid material and realize the push flow. As shown in FIG. Figure 1 As shown, three diversion flower plates 4 are provided, and the specific number thereof increases according to the height dimension of the cracker body 1 .

[0024] In this embodiment, a pressure control valve and a pressure gauge are provided on the discharge pipe 3; the pressure gauge is used to monitor the pressure in the cracker body 1, and the pressure control valve is used to control the opening and closing of the discharge pipe 3; the purpose of providing the pressure control valve and the pressure gauge is to ensure that their working pressure is greater than the saturated water vapor pressure at the process temperature to achieve the sealing of the tank. Specifically, their working pressure is ≥ the saturated vapor pressure of water at 200°C.

[0025] In this embodiment, in order to facilitate the replacement of the diverter plate 4 and internal maintenance, the cracker body 1 is configured as a separable upper tank body 11 and a lower tank body 12, and a flange and a sealing ring are provided at the joint of the upper tank body 11 and the lower tank body 12. The upper tank body 11 and the lower tank body 12 are sealed and connected by a circle of bolts 13 arranged at intervals.

[0026] To ensure a stable temperature for the materials inside, insulation jackets 14 are installed on the outside of the upper and lower tank bodies 11, 12. Each insulation jacket 14 has an oil inlet and an oil outlet. The heating medium is biphenyl. A thermometer 6 is also installed on the cracker body 1 to monitor the internal temperature.

[0027] In this embodiment, the feed pipe 2 is connected to a serpentine heater, and the material is heated by the serpentine heater before entering the cracker body 1.

[0028] In this embodiment, the aperture of the diverter hole 41 is ≥1 mm. The height-to-diameter ratio of the cracker body 1 is ≥3. In this embodiment, the serpentine heater is also connected to a flow meter and a metering pump via a pipeline. The metering pump is used to pump material into the serpentine heater for heating and then pass it into the cracker body 1, and the flow rate is monitored by the flow meter. Among them, the metering pump, pressure control valve, etc. are all electrically connected to the control system so that their opening and closing can be automatically controlled according to design requirements.

[0029] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A recycling cracker for producing polyamide 6 chips, comprising a cracker body (1), wherein a feed pipe (2) is provided at the bottom of the cracker body (1), and a discharge pipe (3) is provided at the top, characterized in that: At least one diversion flower plate (4) is provided in the cracker body (1), and a plurality of diversion holes (41) are provided on the diversion flower plate (4).

2. The recycling cracker for producing polyamide 6 chips according to claim 1, characterized in that: The discharge pipe (3) is provided with a pressure control valve and a pressure gauge.

3. The recycling cracker for producing polyamide 6 chips according to claim 2, characterized in that: The cracker body (1) is provided with an observation hole (5).

4. The recycling cracker for producing polyamide 6 chips according to any one of claims 1 to 3, characterized in that: The cracker body (1) comprises an upper tank body (11) and a lower tank body (12), wherein the upper tank body (11) and the lower tank body (12) are sealed and butted together and connected by a circle of bolts (13) arranged at intervals.

5. The recycling cracker for producing polyamide 6 chips according to claim 4, characterized in that: The outer sides of the upper tank body (11) and the lower tank body (12) are both provided with heat-insulating jackets (14).

6. The recycling cracker for producing polyamide 6 chips according to claim 5, characterized in that: The feed pipe (2) is connected to a serpentine heater.

7. The recycling cracker for producing polyamide 6 chips according to claim 1, characterized in that: The pore diameter of the diversion hole (41) is ≥1 mm.

8. The recycling cracker for producing polyamide 6 chips according to claim 1, characterized in that: The ratio of height to diameter of the cracker body (1) is ≥3.

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