Nylon chip continuous solid phase viscosity enhancement system and processing method

Abstract

The present invention relates to the technical field of polyamide production, in particular to a continuous solid-phase tackification system for nylon chips, comprising a feeding system, a tackification tower, a bulk nitrogen feeding device, and a cooling tower, wherein the downstream of the feeding system is connected to the tackification tower, the bulk nitrogen feeding device is connected to the inside of the tackification tower and is used to transport nitrogen to the inside of the tackification tower, the tackification tower is used to achieve continuous tackification treatment of nylon chips entering the inside, and the cooling tower is connected and arranged downstream of the tackification tower and is used to cool the nylon chips after the tackification treatment. In the present system and treatment method, the reaction temperature in the tackification tower is controlled to be relatively low, the heating temperature of the nylon chips is above the glass transition temperature and below the melting point, and there is no occurrence of side reactions such as degradation; and the molecular weight of the polymer can be effectively increased.

Description

Technical Field

[0001] The invention relates to the technical field of polyamide production, in particular to a nylon chip continuous solid phase viscosity increasing system and a processing method. Background Art

[0002] As one of the five major engineering plastics, nylon has high tensile strength, large elastic modulus, excellent wear resistance and self-lubricating properties, and is widely used in automobile manufacturing, electronic appliances, mechanical equipment, packaging and other industries. There are many varieties of nylon, including nylon 6, nylon 66, nylon 11, nylon 12, nylon 46, nylon 610, nylon 612, nylon 1010, etc., as well as new products such as semi-aromatic nylon 6T and special nylon developed in recent years. Among them, nylon 6 and nylon 66 have the largest output, accounting for more than 90% of nylon output.

[0003] Industrial nylon requires high relative strength and high relative viscosity. Conventional polymerization produces low-viscosity nylon 6 chips (viscosity 2.2-3.0), while nylon 66 has lower viscosity than nylon 6, which limits its application range.

[0004] At present, solid phase polymerization is an effective method for producing high viscosity nylon. The principle is to heat the nylon slices with low relative molecular weight to above the glass transition temperature and below the melting point, and further solid phase polymerization reaction occurs inside the slices. The by-product small molecules (water) diffuse out from the inside of the slices and are taken out of the reaction system with the help of vacuum or inert gas. As the small molecules continue to diffuse, the polymerization reaction inside the slices continues, and the relative molecular mass continues to increase. Summary of the invention

[0005] The present invention solves one of the above-mentioned technical problems, and the technical solution adopted is: a continuous solid-phase thickening system for nylon chips, including a feeding system, a thickening tower, a nitrogen circulation system, and a cooling tower. The downstream of the feeding system is connected to the thickening tower, the nitrogen circulation system is connected to the inside of the thickening tower and is used to transport nitrogen to the inside of the thickening tower. The thickening tower is used to realize continuous thickening treatment of the nylon chips entering the inside, and the cooling tower is connected and arranged downstream of the thickening tower and is used to cool the nylon chips after the thickening treatment.

[0006] In any of the above schemes, it is preferred that the thickening tower includes a thickening tower body which is hollow and has a nitrogen outlet on one side of the top, an upper cone tube and a lower cone tube are respectively provided at the top and bottom of the thickening tower body, a cone tube feed port is provided at the top of the upper cone tube, and a cone tube discharge port is provided at the bottom of the lower cone tube, and a plurality of alternating first-level air distribution equalizers and second-level air distribution equalizers are installed in sequence from top to bottom in the inner cavity of the thickening tower body.

[0007] In any of the above schemes, it is preferred that the first-level air distribution and material distribution device and the second-level air distribution and material distribution device are respectively used to achieve uniform distribution of nylon slices falling into the inner cavity of the viscosity-increasing tower body 1.

[0008] In any of the above schemes, it is preferred that an upper material equalizer is provided in the inner cavity of the upper cone tube, and a lower material equalizer is provided in the inner cavity of the lower cone tube; the viscosity increasing tower body, each of the first-level air distribution equalizers, each of the second-level air distribution equalizers, the upper material equalizer, and the lower material equalizer are all coaxially arranged.

[0009] In any of the above schemes, it is preferred that the first-level air distribution and material equalizer includes a first-level material equalizing upper cone sleeve which is relatively fixed and coaxially arranged with the inner cavity of the viscosity-enhancing tower body, a first-level central material equalizing channel is arranged in the middle of the first-level material equalizing upper cone sleeve, an outer material equalizing channel is formed by the first-level material equalizing upper cone sleeve and the viscosity-enhancing tower body, and a first-level annular air inlet channel is formed in the space between the two circular rings of the first-level material equalizing upper cone sleeve.

[0010] In any of the above schemes, it is preferred that the secondary air distribution and material equalizer includes a secondary material equalizing cone that is relatively fixed and coaxially arranged with the inner cavity of the viscosity-enhancing tower body, and also includes a secondary external air distribution and material equalizing inverted cone cylinder connected to the viscosity-enhancing tower body, the secondary external air distribution and material equalizing inverted cone cylinder and the secondary material equalizing cone form a material equalizing channel, and the space between the two circular rings of the secondary material equalizing cone forms a secondary annular air inlet inner channel. The secondary external air distribution and material equalizing inverted cone cylinder and the viscosity-enhancing tower body form a secondary annular air inlet outer channel.

[0011] In any of the above schemes, it is preferred that the lower-mouth material equalizer is composed of a three-stage lower-mouth material equalizer, a two-stage lower-mouth material equalizer, and a first-stage lower-mouth material equalizer coaxially arranged from top to bottom.

[0012] In any of the above schemes, it is preferred that the three-stage lower material equalizer includes a coaxially arranged three-stage middle cone and a three-stage outer cone, a three-stage inner annular lower material equalizing channel is formed between the three-stage outer cone and the three-stage middle cone, and a three-stage outer annular lower material equalizing channel is formed between the three-stage outer cone and the inner wall of the lower cone tube.

[0013] In any of the above schemes, it is preferred that the secondary lower material equalizer includes a secondary outer shell cone which is arranged directly below the third-level middle cone and coaxially therewith, the center of the secondary outer shell cone is a secondary inner annular lower material equalizing channel, and a secondary outer annular lower material equalizing channel is formed between the secondary outer shell cone and the inner wall of the lower cone tube.

[0014] In any of the above schemes, preferably, the first-stage lower material equalizer includes a first-stage intermediate cone arranged directly below and coaxially with the second-stage intermediate cone, and a first-stage outer annular lower material equalizing channel is formed between the inner wall of the lower cone tube of the first-stage intermediate cone.

[0015] In any of the above schemes, it is preferred that the upper material equalizer is composed of a primary upper material equalizer and a secondary upper material equalizer which are coaxially arranged from top to bottom.

[0016] In any of the above schemes, preferably, the first-stage upper material equalizer includes a first-stage upper cone coaxially and fixedly arranged inside the upper cone tube, and the space between the first-stage upper cone and the inner wall of the upper cone tube forms a first-stage annular upper material equalizing channel.

[0017] In any of the above schemes, it is preferred that the secondary upper material equalizer includes a secondary upper inverted cone sleeve which is coaxially and fixedly arranged inside the upper cone tube, a secondary central upper material equalizing channel is arranged in the middle of the secondary upper inverted cone sleeve, and a secondary outer annular upper material equalizing channel is formed in the space between the secondary upper inverted cone sleeve and the inner wall of the upper cone tube.

[0018] After receiving the nylon chips into the thickening tower, the evenly dispersed and distributed materials are dispersed through multiple material leveling components to make the nylon particles flow from top to bottom in a plug flow manner, ensuring that the residence time of the nylon chips in the thickening tower is consistent, ultimately ensuring the uniformity of the thickening of the nylon chips, and preventing local material from not flowing and sticking.

[0019] The upper material distributor is mainly used to distribute the slices that have just entered from the upper conical tube feed port, to achieve the first distribution, improve the material dispersion effect, and ensure the distribution effect.

[0020] In any of the above schemes, preferably, the top angles of the three-stage lower material equalizer, the two-stage lower material equalizer, and the first-stage lower material equalizer are all 30°-50°. Setting a suitable taper and angle can effectively ensure the effectiveness of bulking, and the angle is not set too large or too small, so that the height size of the entire upper material distribution inner cone can be effectively controlled while ensuring the bulking effect and speed.

[0021] When the nylon chips are in contact with nitrogen and fully thickened in the inner cavity of the thickening tower, the lower material distributor can better ensure that the treated nylon chips can be effectively distributed and gathered, thereby improving the effect of discharging the nylon chips outward.

[0022] Setting the angles of each component of the three-stage lower outlet material distributor to appropriate tapers and included angles can effectively ensure the effectiveness of material discharging and aggregation. The included angle should not be set too large or too small, so that the height of the entire lower distribution inner cone can be effectively controlled to match the size of the inner cavity of the viscosity-enhancing tower while ensuring the material discharging and aggregation effect and the appropriate speed.

[0023] It ensures uniform transition when receiving nylon materials from above, and ensures the size matching, which can effectively ensure the smoothness and uniformity of the material when it is guided outward, thus improving the discharge effect.

[0024] The multiple alternatingly arranged first-level air distribution and distribution equalizers and second-level air distribution and distribution equalizers can be arranged in sequence from the top to the bottom, so as to ensure that the material can be continuously distributed for multiple times during the nylon material viscosity increasing treatment process, and can ensure that the material is fully in contact with the nitrogen entering the interior, thereby ensuring the effect of the viscosity increasing treatment.

[0025] Setting the appropriate taper and angle can effectively ensure the effectiveness of bulking, and the angle should not be set too large or too small, so that the height size of the entire inner wind-distributing material-evening cone can be effectively controlled while ensuring the bulking effect and speed.

[0026] In any of the above schemes, it is preferred that at least one inner air inlet pipe connected to the first-level air distribution and material equalizer is connected to the inner cavity thereof through an air inlet, and the outer end of each inner air inlet pipe extends to the outside of the viscosity enhancing tower body.

[0027] In any of the above schemes, preferably, at least one inner air inlet pipe connected to the secondary air distribution and equalizing device through the air inlet is connected to the secondary air distribution and equalizing device, and the outer end of each inner air inlet pipe extends to the outside of the viscosity-enhancing tower body. At least one outer air inlet pipe connected to the secondary air distribution and equalizing device through the air inlet is connected to the secondary air distribution and equalizing device, and the outer end of each outer air inlet pipe extends to the outside of the viscosity-enhancing tower body.

[0028] In any of the above solutions, preferably, each of the inner air inlet pipes and the outer air inlet pipes is used to receive nitrogen from the outside.

[0029] Through the combined action of the upper material distributor in the thickening tower, the first-stage air distribution distributor and the second-stage air distribution distributor alternately arranged in the thickening tower body, and the lower material distributor, the nylon particles can flow from top to bottom in a plug flow manner, ensuring that the residence time of the nylon slices in the thickening tower is consistent, ultimately ensuring the uniformity of the thickening of the nylon slices, and preventing local material from not flowing and sticking.

[0030] The nitrogen is blown upward from the bottom, and the slices are laid downward from the top in sequence. During this process, the nitrogen is fully in contact with the nylon slices. The nylon slices stay in the viscosity increasing tower for 12 to 36 hours before the viscosity increasing process is completed.

[0031] In any of the above schemes, it is preferred that the nitrogen scrubbing is divided into two stages, and the two stages use independent water pumps, heat exchangers and circulating water pipelines. The washing water for the lower washing is cooled by circulating water, and the circulating water used here can meet the requirements by passing through a cooling tower, and the low-temperature washing water for the upper washing is cooled by ice water. The lower washing performs a first-level washing and cooling of the nitrogen, and the upper washing further washes and cools the nitrogen to meet the air outlet requirements of the washing tower. The upper spraying is performed on the basis of the cooling of the lower washing, and the required cooling capacity is greatly reduced, so that the energy consumption required for producing cooling capacity is greatly reduced.

[0032] The washing tower includes a washing tower body, a base is installed at the bottom of the washing tower body, an air outlet is installed at the top of the washing tower body, an air inlet is installed on one side of the lower part of the washing tower body, an upper spray device and a lower spray device are respectively installed at the upper and lower parts of the inner cavity of the washing tower body, an upper bulk material air intake device is installed in the inner cavity of the washing tower body between the upper spray device and the lower spray device, and a plurality of vertical hanging cover inspection manholes are installed in sequence from top to bottom on the washing tower body.

[0033] The device adopts an upper spray device and a lower spray device to realize double spraying, which can effectively improve the effect of spray washing, better ensure that the incoming nitrogen is quickly sprayed with washing water, and effectively improve the washing speed.

[0034] At the same time, an upper bulk material air intake device is provided to separate the upper and lower sprays, and the upper spray can use low-temperature washing water to wash and cool the nitrogen.

[0035] The scrubbing tower uses scrubbing water to wash and cool the nitrogen. The cooling of the scrubbing water mainly relies on the heat exchanger. Different heat exchangers use different cooling media to obtain scrubbing water of different temperatures.

[0036] The spraying adopts the method of spraying washing water from top to bottom, and nitrogen enters from the air inlet at the bottom of the washing tower body. Water is sprayed on the packing from top to bottom and flows down along the surface of the packing to form a water film on the surface of the packing. Nitrogen flows from bottom to top in countercurrent with the liquid through the gaps between the packings continuously, and the gas-liquid two phases are in close contact on the surface of the packing for heat and mass transfer.

[0037] The nitrogen first passes through the lower spray device to achieve the initial spraying and cooling, and then continues upward to pass through the upper spray device to achieve the secondary spraying and cooling, thereby improving the washing and cooling effects.

[0038] In any of the above solutions, preferably, a wire mesh demister is installed in the air outlet. The wire mesh demister installed at the outlet can quickly remove the mist entrained in the tail gas.

[0039] In any of the above schemes, it is preferred that the upper spray device includes a plurality of upper fixed seats fixedly mounted on the side wall of the inner cavity of the washing tower body, the inner end of a horizontally arranged upper washing water inlet pipe extends into the inner cavity of the washing tower body and is fixed to the corresponding upper fixed seat through a corresponding upper U-shaped clamp, an upper washing water inlet is provided at the outer end of the upper washing water inlet pipe, and a plurality of upper nozzles are arranged at intervals at the bottom of the middle section of the upper washing water inlet pipe.

[0040] The upper wash water inlet, the lower wash water inlet and the corresponding wash water outlet are matched with the corresponding circulating water pump and the heat exchanger through pipelines.

[0041] After receiving the low-temperature water flow from the external circulating water pump, the upper spray device will first enter through the upper washing water inlet, and then due to the high pressure of the water flow, it will be continuously sprayed from the upper nozzle, sprayed on the upper packing layer, and flow down along the surface of the packing, forming a water film on the surface of the packing. The nitrogen gas continuously passes through the gaps between the packings from bottom to top in countercurrent with the liquid, and the gas-liquid two phases are in close contact on the surface of the packing for heat and mass transfer, so as to fully wash and cool the nitrogen containing impurities.

[0042] In any of the above schemes, preferably, an upper wash water replenishment port is installed on the side wall of the washing tower body below the upper wash water inlet. When the upper spray washing water is insufficient, water can be replenished into the tower through the upper wash water replenishment port to ensure sufficient water supply.

[0043] In any of the above schemes, it is preferred that the lower spray device includes a plurality of lower fixing seats fixedly mounted on the side wall of the inner cavity of the washing tower body, the inner end of a horizontally arranged lower wash water inlet pipe extends into the inner cavity of the washing tower body and is fixed to the corresponding lower fixing seat through a corresponding lower U-shaped clamp, a lower wash water inlet is provided at the outer end of the lower wash water inlet pipe, and a plurality of lower nozzles are arranged at intervals at the bottom of the middle section of the lower wash water inlet pipe.

[0044] After receiving the water flow from the external circulating water pump, the lower spray device will first enter through the lower washing water inlet, and then due to the high pressure of the water flow, it will be continuously sprayed out from the lower nozzle, sprayed on the lower packing layer, and flow down along the surface of the packing, forming a water film on the surface of the packing. The nitrogen and the liquid are countercurrent from bottom to top and continuously pass through the gaps between the packings. On the surface of the packing, the gas-liquid two phases are in close contact for heat and mass transfer, so as to fully wash and cool the nitrogen containing impurities. Cooperating with the upper spray device above, better spray washing can be achieved, effectively improving the washing effect and efficiency, and capable of quickly washing a large amount of nitrogen.

[0045] In any of the above schemes, preferably, a lower wash water replenishing port is installed on the side wall of the washing tower body below the lower wash water inlet. When the lower spray washing water is insufficient, water can be replenished into the tower through the lower wash water replenishing port to ensure sufficient water supply.

[0046] In any of the above schemes, preferably, each of the upper nozzles and each of the lower nozzles is a conical spiral nozzle. The use of the conical spiral nozzle can better ensure the spraying effect and improve the adequacy of the contact between the spray washing water and the nitrogen.

[0047] In any of the above schemes, it is preferred that the upper bulk material air intake device includes an upper perforated spray inclined plate obliquely arranged on the inner cavity side wall of the washing tower body, and a liquid level upper gauge interface, an overflow port, a wash water outlet, a liquid level gauge lower interface, and a sewage outlet are installed in sequence from top to bottom on the side wall of the washing tower body corresponding to the upper part of the upper perforated spray inclined plate, and a plurality of vertically arranged air intake ducts are spaced apart along the surface of the upper perforated spray inclined plate.

[0048] The upper bulk material air intake device separates the upper and lower washing water to prevent the liquid from the upper spray from entering the lower spray. The gas washed by the lower spray can enter the upper spray through the vertical air intake duct of the upper bulk material air intake device.

[0049] There is a certain amount of water in the lower part of the upper and lower sprays, so that impurities in the water can settle naturally. A liquid level gauge is installed to detect the liquid level of this part of the water. When the liquid level is low, water is replenished through the water replenishment port, and when the liquid level is high, excess water is discharged through the overflow port.

[0050] At the same time, the liquid level gauge connected to the upper interface of the liquid level gauge and the lower interface of the liquid level gauge can effectively observe and measure the current water level status.

[0051] The sewage outlet can discharge the dirt adhering to the upper perforated spray inclined plate and the lower spray inclined plate when the inside of the washing tower is cleaned after the spraying is completed.

[0052] Setting a proper tilt angle can ensure that the upper and lower sprays can drain the washing water completely.

[0053] In any of the above schemes, preferably, a cone tube protection cap is fixedly installed on the top of each of the air intake ducts, and a spacing space is provided between the cone tube protection cap and the top of the corresponding air intake duct.

[0054] The cone tube protective cap can effectively prevent the sprayed liquid from entering the air intake duct, ensuring that the nitrogen gas entering can be quickly discharged from the surrounding space, reducing the probability of the upper sprayed liquid entering the lower spray, and at the same time playing the role of air uniformity.

[0055] In any of the above schemes, preferably, a lower spray inclined plate is installed in the inner cavity of the washing tower body below the lower spray device, and the incoming air enters through the air inlet on the side wall of the washing tower.

[0056] In any of the above schemes, preferably, a filler layer of a certain thickness is installed in the inner cavity of the washing tower body below the upper spray device.

[0057] In any of the above schemes, preferably, a filler layer of a certain thickness is installed in the inner cavity of the washing tower body below the lower spray device.

[0058] In any of the above schemes, it is preferred that the feeding system adopts a metering and conveying device, the feed port of the metering and conveying device is used to receive the raw materials, and the outlet of the metering and conveying device is used to communicate with the inlet end of the viscosity increasing tower.

[0059] The metering and conveying device can be an existing product. There is no design improvement in the equipment here, so it will not be described in detail.

[0060] In any of the above schemes, it is preferred that the nitrogen circulation system includes a nitrogen preheater, the lower inlet end of the nitrogen preheater is connected to the top of the thickening tower and is used to receive the hot nitrogen discharged from the thickening tower, the upper outlet end of the nitrogen preheater is connected to the inlet end of the nitrogen treatment device, the upper inlet end of the nitrogen preheater is connected to the top outlet end of the nitrogen treatment device, and the lower outlet end of the nitrogen preheater is connected to a multi-stage nitrogen conveying assembly, and the multi-stage nitrogen conveying assembly is used to realize multi-path delivery of increased temperature nitrogen to the thickening tower.

[0061] In any of the above schemes, it is preferred that the nitrogen circulation system includes a multi-stage nitrogen delivery assembly, and the multi-stage nitrogen delivery assembly is respectively connected to the upper part, the middle part and the lower part of the viscosity increasing tower.

[0062] In any of the above schemes, it is preferred that the multi-stage nitrogen delivery assembly includes a plurality of groups of primary nitrogen delivery branch components, secondary nitrogen delivery branch components, and tertiary nitrogen delivery branch components arranged in parallel, and the primary nitrogen delivery branch components, the secondary nitrogen delivery branch components, and the tertiary nitrogen delivery branch components are all connected to the lower outlet end of the nitrogen preheater through a main pipe.

[0063] In any of the above schemes, preferably, the primary nitrogen delivery branch component includes a primary delivery branch pipeline, on which a primary nitrogen compressor and a primary heat exchanger are sequentially installed in series according to the flow direction of nitrogen;

[0064] In any of the above schemes, preferably, the primary nitrogen delivery branch component includes a secondary delivery branch pipeline, on which a secondary nitrogen compressor and a secondary heat exchanger are sequentially installed in series according to the flow direction of nitrogen;

[0065] In any of the above schemes, it is preferred that the three-stage nitrogen delivery branch component includes a three-stage delivery branch pipeline, on which a three-stage nitrogen compressor, a three-stage deaerator, and a three-stage heat exchanger are installed in series in sequence according to the flow direction of nitrogen.

[0066] In any of the above schemes, preferably, the nitrogen circulation system includes a washing tower, the top outlet end of the washing tower is connected to the upper inlet end of the nitrogen preheater through an outlet pipeline, a demister unit is installed on the outlet pipeline, the lower inlet end of the washing tower is connected to the upper outlet end of the nitrogen preheater through a pipeline, a circulation pipeline is provided on one side of the washing tower, the inlet end of the circulation pipeline is connected to the bottom outlet end of the washing tower, the reflux end of the circulation pipeline is connected to the reflux port at the top of the washing tower, and a circulating water pump and a circulating water heat exchanger unit are arranged in series in the circulation pipeline according to the flow direction of the circulating water.

[0067] In any of the above schemes, it is preferred that a high-purity nitrogen replenishing port is provided on the pipeline between the viscosity increasing tower and the nitrogen preheater, and the high-purity nitrogen replenishing port can replenish the consumed nitrogen in time, effectively ensuring the continuity of the system nitrogen.

[0068] The present invention also provides a nylon chip continuous solid phase viscosity enhancement treatment method, comprising the following steps:

[0069] S1: Measuring and conveying nylon chips material and allowing the material to enter the nylon chips continuous solid phase tackifying tower of the system;

[0070] S2: Nylon chips flow from top to bottom in the viscosity increasing tower in a plug flow manner;

[0071] S3: nitrogen is introduced into the viscosity increasing tower to fully contact the nylon chips;

[0072] The role of the nitrogen provided here is to take away the small molecules (water) produced as a byproduct of the viscosity increasing process.

[0073] The specific steps of introducing nitrogen in S3 are as follows: the nitrogen is divided into three streams and enters the viscosity increasing tower from the upper, middle and lower parts of the viscosity increasing tower respectively, and an independent nitrogen compressor and nitrogen heat exchanger are provided on each nitrogen pipeline to accurately control the flow rate and temperature of each nitrogen stream to achieve precise control of the slice temperature in the viscosity increasing tower. A deaerator may be provided on at least one of the pipelines, and the deaerator may deoxygenate the nitrogen to ensure the purity of the nitrogen.

[0074] The distribution of internal parts in the thickening tower enables the nylon particles to flow from top to bottom in a plug flow manner, ensuring that the residence time of the nylon chips in the thickening tower is consistent, ultimately ensuring the uniformity of the thickening of the nylon chips, while preventing local material from not flowing and sticking.

[0075] The nylon chips are heated by three streams of nitrogen at the upper, middle and lower parts in the viscosity increasing tower. The temperature of the upper chips is controlled at 80-150°C, the temperature of the middle chips is controlled at 140-170°C, and the temperature of the lower chips is controlled at 160-180°C.

[0076] This system adopts nitrogen closed-loop circulation. Hot nitrogen is discharged from the top of the viscosity increasing tower, enters the nitrogen preheater and exchanges heat with the cold nitrogen coming out of the demister, and then enters the scrubbing tower from the bottom of the scrubbing tower. The nitrogen is washed and cooled by the scrubbing tower to remove the small molecules and water carried by the viscosity increasing process.

[0077] The washed nitrogen enters the demister for demisting and drying, enters the nitrogen preheater for preheating, and then enters the viscosity increasing tower in three streams.

[0078] The hot nitrogen entering the upper part of the viscosity increasing tower is a part that has been washed, demisted and preheated by the nitrogen preheater. This nitrogen is pressurized by the first-stage nitrogen compressor and heated by the first-stage nitrogen heat exchanger before entering the viscosity increasing tower from the upper part.

[0079] The hot nitrogen entering the middle of the viscosity increasing tower is a part that has been washed, demisted and preheated by the nitrogen preheater. This nitrogen is pressurized by the secondary nitrogen compressor and heated by the secondary nitrogen heat exchanger before entering the viscosity increasing tower from the middle.

[0080] The hot nitrogen entering the lower part of the viscosity increasing tower is a part that has been preheated by the washing and demisting and nitrogen preheater. This nitrogen enters the viscosity increasing tower from the lower part after being pressurized by the three-stage nitrogen compressor, deoxygenated by the three-stage deaerator and heated by the three-stage nitrogen heat exchanger.

[0081] S4: maintaining steps S2-S3 and allowing the nylon chips to stay in the viscosity increasing tower for 12 to 36 hours to complete the viscosity increasing process;

[0082] S5: After the viscosity increasing process is completed, the nylon slices after viscosity increasing in the viscosity increasing tower enter the cooling tower for cooling;

[0083] S6: Continuously cool under the cooling effect of the circulating water cooler in the cooling tower, and after cooling to the standard, it is pneumatically conveyed to the finished product warehouse.

[0084] In any of the above schemes, it is preferred that the nylon chip continuous solid phase viscosity enhancement system described in S1 is the nylon chip continuous solid phase viscosity enhancement system described in any one of claims 1 to 7.

[0085] In any of the above schemes, it is preferred that the temperature of the slices located at the upper part of the viscosity increasing tower is controlled at 80-150°C, the temperature of the slices located in the middle part is controlled at 140-170°C, and the temperature of the slices located at the lower part is controlled at 160-180°C.

[0086] The beneficial effects of the present invention are embodied in:

[0087] 1) In the present system and treatment method, the reaction temperature in the viscosity increasing tower is controlled to be relatively low, the heating temperature of the nylon chips is above the glass transition temperature and below the melting point, and there is no side reaction such as degradation; and the molecular weight of the polymer can be effectively increased.

[0088] 2) Nitrogen is divided into three streams and enters different parts of the viscosity increasing tower. Each stream of nitrogen has an independent nitrogen compressor and nitrogen heat exchanger, which can accurately control the flow and temperature of each stream of nitrogen to achieve precise control of the slice temperature in the viscosity increasing tower.

[0089] 3) This system can promptly remove small molecules and water as byproducts of the viscosity-increasing process through the scrubbing tower, and the deaerator can ensure the purity of the nitrogen entering the viscosity-increasing tower.

[0090] 4) The system sets a deaerator in the nitrogen at the bottom of the viscosity increasing tower, which can reduce the volume of the deaerator and reduce the investment cost and operation cost.

[0091] 5) The nitrogen washing system is divided into two stages, and the two stages use independent water pumps, heat exchangers and circulating water pipelines. The washing water for the lower washing is cooled by circulating water. The circulating water used here can meet the requirements through the cooling tower. The low-temperature washing water for the upper washing is cooled by ice water. The lower washing washes and cools the nitrogen in one stage, and the upper washing further washes and cools the nitrogen to meet the air outlet requirements of the washing tower. The upper spraying is used to cool the nitrogen after the lower washing has cooled down, and the required cooling capacity is greatly reduced, so the energy consumption required to produce cooling capacity is greatly reduced. In order to further ensure the air outlet temperature and washing efficiency of the washing tower, it can be achieved by continuing to increase the number of washing stages of the washing tower. BRIEF DESCRIPTION OF THE DRAWINGS

[0092] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the specific embodiments or the description of the prior art. In all the drawings, similar elements or components are generally identified by similar reference numerals. In the drawings, the elements or components are not necessarily drawn according to the actual scale.

[0093] Figure 1 It is a process flow chart of the present invention.

[0094] Figure 2 It is a schematic diagram of the internal structure of the viscosity increasing tower of the present invention.

[0095] Figure 3 It is a schematic diagram of the internal structure of the cooling tower of the present invention.

[0096] Figure 1-3 The names of the labels are as follows: 1. First-stage nitrogen compressor; 2. First-stage heat exchanger; 3. Second-stage nitrogen compressor; 4. Second-stage heat exchanger; 5. Third-stage nitrogen compressor; 6. Deaerator; 7. Third-stage heat exchanger; 8. Thickening tower; 9. Cooling tower; 10. Measuring and conveying device; 11. Nitrogen preheater; 12. Defogger unit; 1201. Defogger; 1202. Demisting opening valve; 13. Scrubber; 14. Circulating water pump; 15. Tower circulating water heat exchanger unit; 1501. Tower circulating water heat exchanger; 1502. Circulating opening valve; 17. Upper port equalizer; 18. First-stage air distribution equalizer; 19. Second-stage air distribution equalizer; 20. Lower port equalizer; 21. Nitrogen outlet; 22, upper cone tube; 23, lower cone tube; 24, cone tube feed port; 25, cone tube discharge port; 26, first-level equalizing upper cone sleeve; 27, first-level center equalizing channel; 28, outer equalizing channel; 29, first-level annular air inlet channel; 30, second-level equalizing cone; 31, second-level external air distribution equalizing inverted cone barrel; 32, equalizing channel; 33, second-level annular air inlet inner channel; 34, second-level annular air inlet outer channel; 35, third-level lower outlet equalizer; 36, second-level lower outlet equalizer; 37, first-level lower outlet equalizer; 38, third-level middle vertebra; 39, third-level outer vertebra; 40, third-level inner annular lower equalizing channel; 41, third-level outer annular lower equalizing channel ;42. Secondary outer casing cone;43. Secondary inner annular lower material equalizing channel;44. Secondary outer annular lower material equalizing channel;45. Primary intermediate cone;46. Primary outer annular lower material equalizing channel;47. Primary upper material equalizer;48. Secondary upper material equalizer;49. Primary upper cone;50. Primary annular upper material equalizing channel;51. Secondary upper inverted cone sleeve;52. Secondary central upper material equalizing channel;53. Secondary outer annular upper material equalizing channel;54. Washing tower body;55. Installation base;56. Air outlet;57. Vertical cover inspection manhole;58. Wire mesh demister;59. Upper fixing seat;60. Upper wash water inlet pipe;61. Upper U-shaped clamp;62. Wash water inlet; 63, upper nozzle; 64, upper wash water replenishment port; 65, lower fixed seat; 66, lower wash water inlet pipe; 67, lower wash water inlet; 68, lower nozzle; 69, lower wash water replenishment port; 70, upper spray inclined plate with holes; 71, overflow port; 72, wash water outlet; 73, upper level gauge interface; 74, lower level gauge interface; 75, sewage outlet; 76, air inlet duct; 77, cone tube protective cap; 78, partition space; 79, lower spray inclined plate; 80, lower U-shaped clamp; 81, upper packing layer; 82, lower packing layer; 83, air inlet; 84, upper spray device; 85, lower spray device; 86, upper bulk material air inlet device. DETAILED DESCRIPTION

[0097] The following embodiments of the technical solution of the present invention are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and are therefore only used as examples, and cannot be used to limit the protection scope of the present invention.

[0098] like Figure 1-3 As shown in the figure, the continuous solid-phase thickening system for nylon chips includes a feeding system 10, a thickening tower 8, a nitrogen circulation system, and a cooling tower 9. The downstream of the feeding system 10 is connected to the thickening tower 8, and the nitrogen circulation system is connected to the inside of the thickening tower 8 and is used to transport nitrogen to the inside of the thickening tower 8. The thickening tower 8 is used to achieve continuous thickening treatment of the nylon chips entering the inside, and the cooling tower 9 is connected to the downstream of the thickening tower 8 and is used to cool the nylon chips after the thickening treatment.

[0099] In any of the above schemes, it is preferred that the thickening tower includes a thickening tower body which is hollow and has a nitrogen outlet 21 on one side of the top, an upper cone tube 22 and a lower cone tube 23 are respectively provided at the top and bottom of the thickening tower body, a cone tube feed port 24 is provided at the top of the upper cone tube 22, and a cone tube discharge port 25 is provided at the bottom of the lower cone tube 23, and a plurality of alternating first-stage air distribution equalizers 18 and second-stage air distribution equalizers 19 are installed in the inner cavity of the thickening tower body in sequence from top to bottom.

[0100] In any of the above schemes, it is preferred that the first-level air distribution and material distribution device 18 and the second-level air distribution and material distribution device 19 are respectively used to achieve uniform distribution of nylon slices falling into the inner cavity of the viscosity-increasing tower body.

[0101] In any of the above schemes, it is preferred that an upper material equalizer 17 is provided in the inner cavity of the upper cone tube 22, and a lower material equalizer 20 is provided in the inner cavity of the lower cone tube 23; the viscosity increasing tower body 19, each of the first-level air distribution material equalizers 18, each of the second-level air distribution material equalizers 19, the upper material equalizer 17, and the lower material equalizer 20 are all coaxially arranged.

[0102] In any of the above schemes, it is preferred that the first-level air distribution and material equalizer 18 includes a first-level material equalizing upper cone sleeve 26 which is relatively fixed and coaxially arranged with the inner cavity of the viscosity-enhancing tower body, a first-level central material equalizing channel 27 is arranged in the middle of the first-level material equalizing upper cone sleeve 26, an outer material equalizing channel 28 is formed by the first-level material equalizing upper cone sleeve 26 and the viscosity-enhancing tower body, and a first-level annular air inlet channel 29 is formed in the space between the two circular rings of the first-level material equalizing upper cone sleeve 26.

[0103] In any of the above schemes, it is preferred that the secondary air distribution and material equalizer 19 includes a secondary material equalizing cone 30 which is relatively fixed and coaxially arranged with the inner cavity of the thickening tower body, and also includes a secondary external air distribution and material equalizing inverted cone cylinder 31 connected to the thickening tower body, the secondary external air distribution and material equalizing inverted cone cylinder 31 and the secondary material equalizing cone 30 form a material equalizing channel 32, the space between the two circular rings of the secondary material equalizing cone 30 forms a secondary annular air inlet inner channel 33, and the secondary external air distribution and material equalizing inverted cone cylinder 31 and the thickening tower body form a secondary annular air inlet outer channel 34.

[0104] In any of the above schemes, it is preferred that the lower material equalizer 20 is composed of a three-stage lower material equalizer 35, a second-stage lower material equalizer 36, and a first-stage lower material equalizer 37 which are coaxially arranged from top to bottom.

[0105] In any of the above schemes, it is preferred that the three-stage lower-mouth material equalizer 35 includes a coaxially arranged three-stage middle cone 38 and a three-stage outer cone 39, a three-stage inner annular lower material equalizing channel 40 is formed between the three-stage outer cone 39 and the three-stage middle cone 38, and a three-stage outer annular lower material equalizing channel 41 is formed between the three-stage outer cone 39 and the inner wall of the lower cone tube 23.

[0106] In any of the above schemes, it is preferred that the secondary lower material equalizer 36 includes a secondary outer cone 42 which is arranged directly below the third-level intermediate cone 38 and coaxially therewith, the center of the secondary outer cone 42 is a secondary inner annular lower material equalizing channel 43, and a secondary outer annular lower material equalizing channel 44 is formed between the secondary outer cone 42 and the inner wall of the lower cone tube 23.

[0107] In any of the above schemes, it is preferred that the first-level lower material equalizer 37 includes a first-level intermediate cone 45 arranged directly below and coaxially with the second-level intermediate cone, and a first-level outer annular lower material equalizing channel 46 is formed between the first-level intermediate cone 45 and the inner wall of the lower cone tube 23.

[0108] In any of the above schemes, it is preferred that the upper material equalizer 17 is composed of a primary upper material equalizer 47 and a secondary upper material equalizer 48 which are coaxially arranged from top to bottom.

[0109] In any of the above schemes, it is preferred that the first-level upper material equalizer 47 includes a first-level upper cone 49 coaxially and fixedly arranged inside the upper cone tube 22, and the space between the first-level upper cone 49 and the inner wall of the upper cone tube 22 forms a first-level annular upper material equalizing channel 50.

[0110] In any of the above schemes, it is preferred that the secondary upper material equalizer 48 includes a secondary upper inverted cone sleeve 51 which is coaxially and fixedly arranged inside the upper cone tube 22, a secondary central upper material equalizing channel 52 is arranged in the middle of the secondary upper inverted cone sleeve 51, and a secondary outer annular upper material equalizing channel 53 is formed in the space between the secondary upper inverted cone sleeve 51 and the inner wall of the upper cone tube 22.

[0111] After receiving the nylon slices and entering it, the thickening tower 8 can realize the flow of nylon particles from top to bottom in a plug flow manner through the uniform dispersion and distribution effects of multiple material leveling components, ensuring that the nylon slices stay in the thickening tower 8 for a consistent time, ultimately ensuring the uniformity of the thickening of the nylon slices, and preventing local material from not flowing and sticking.

[0112] The upper material distributor 17 is mainly used to distribute the slices just entering from the upper conical tube feed port 24, so as to achieve the first distribution, improve the material distribution effect and ensure the distribution effect.

[0113] In any of the above schemes, it is preferred that the top angles of the three-stage lower material equalizer 35, the two-stage lower material equalizer 36, and the first-stage lower material equalizer 37 are all 30°-50°. Setting a suitable taper and angle can effectively ensure the effectiveness of bulking, and the angle is not set too large or too small, so that the height size of the entire upper material distribution inner cone can be effectively controlled while ensuring the bulking effect and speed.

[0114] When the nylon chips are in contact with nitrogen and fully thickened in the inner cavity of the thickening tower body, the lower material distributor 20 can better ensure that the treated nylon chips can be effectively distributed and gathered, thereby improving the effect of discharging the nylon chips outward.

[0115] Setting the angles of the components of the three-stage lower material distributor 35 to appropriate tapers and included angles can effectively ensure the effectiveness of material discharging and gathering. The included angle should not be set too large or too small, so that the height size of the entire lower material distribution inner cone can be effectively controlled to match the size of the inner cavity of the lower cone tube 23 while ensuring the material discharging and gathering effect and the appropriate speed.

[0116] It ensures uniform transition when receiving nylon materials from above, and ensures the size matching, which can effectively ensure the smoothness and uniformity of the material when it is guided outward, thus improving the discharge effect.

[0117] Multiple alternating first-stage air distribution equalizers 18 and second-stage air distribution equalizers 19 can be arranged in sequence from top to bottom, so as to ensure that the material can be continuously distributed multiple times during the nylon material viscosity increasing treatment process, and can ensure that the material is fully in contact with the nitrogen entering the interior, thereby ensuring the effect of the viscosity increasing treatment.

[0118] Setting the appropriate taper and angle can effectively ensure the effectiveness of bulking, and the angle should not be set too large or too small, so that the height size of the entire inner wind-distributing material-evening cone can be effectively controlled while ensuring the bulking effect and speed.

[0119] In any of the above schemes, it is preferred that at least one inner air inlet pipe connected to the first-level air distribution and material equalizer 18 is connected to the inner cavity thereof through an air inlet, and the outer end of each inner air inlet pipe extends to the outside of the viscosity enhancing tower body.

[0120] In any of the above schemes, it is preferred that at least one internal air inlet pipe connected to the secondary air distribution and equalizer 19 is connected to the secondary air distribution and equalizer 19, and the outer end of each internal air inlet pipe extends to the outside of the thickening tower body. At least one external air inlet pipe connected to the secondary air distribution and equalizer 19 is connected to the secondary air distribution and equalizer 19, and the outer end of each external air inlet pipe extends to the outside of the thickening tower body.

[0121] In any of the above solutions, preferably, each of the inner air inlet pipes and the outer air inlet pipes is used to receive nitrogen from the outside.

[0122] Through the combined action of the upper material distributor 17 in the thickening tower 8, the first-stage air distribution material distributor 18 and the second-stage air distribution material distributor 19 and the lower material distributor 20 arranged alternately in the thickening tower body, the nylon particles can flow from top to bottom in a plug flow manner, ensuring that the residence time of the nylon slices in the thickening tower 8 is consistent, ultimately ensuring the uniformity of the thickening of the nylon slices, and preventing local material from not flowing and sticking.

[0123] The nitrogen is blown upward from the bottom, and the slices are laid downward from the top in sequence. During this process, the nitrogen is fully in contact with the nylon slices. The nylon slices stay in the viscosity increasing tower for 12 to 36 hours before the viscosity increasing process is completed.

[0124] In any of the above schemes, it is preferred that the washing tower 13 includes a washing tower body 54, a base 55 is installed at the bottom of the washing tower body 54, an air outlet 56 is installed at the top of the washing tower body 54, an air inlet 83 is installed on one side of the lower part of the washing tower body 54, an upper spray device 84 and a lower spray device 85 are respectively installed at the upper and lower parts of the inner cavity of the washing tower body 54, an upper bulk material air intake device 86 is installed in the inner cavity of the washing tower body 54 between the upper spray device 84 and the lower spray device 85, and a plurality of vertical hanging cover inspection manholes 57 are installed on the washing tower body 54 from top to bottom.

[0125] The device uses an upper spray device 84 and a lower spray device 85 to achieve double spraying, which can effectively improve the effect of spray washing, better ensure that the incoming nitrogen is quickly sprayed with washing water, and effectively increase the washing speed.

[0126] At the same time, the upper bulk material air intake device 86 can be set to separate the upper and lower sprays, and the upper spray can use low-temperature washing water to wash and cool the nitrogen.

[0127] The scrubbing tower uses scrubbing water to wash and cool the nitrogen. The cooling of the scrubbing water mainly relies on the heat exchanger. Different heat exchangers use different cooling media to obtain scrubbing water of different temperatures.

[0128] The washing water is sprayed from top to bottom, and the nitrogen enters from the air inlet 83 at the bottom of the washing tower body 54. The water is sprayed on the packing from top to bottom and flows down along the surface of the packing to form a water film on the surface of the packing. The nitrogen flows from bottom to top in countercurrent with the liquid and continuously passes through the gaps between the packings. The gas-liquid two phases are in close contact on the surface of the packing for heat and mass transfer.

[0129] The nitrogen first passes through the lower spray device 85 to achieve the initial spraying and cooling, and then continues upward to pass through the upper spray device 84 to achieve the secondary spraying and cooling, thereby improving the washing and cooling effects.

[0130] In any of the above solutions, preferably, a wire mesh demister 58 is installed in the air outlet 56. The wire mesh demister 58 installed at the outlet can quickly remove the mist entrained in the exhaust gas.

[0131] In any of the above schemes, it is preferred that the upper spray device 84 includes a plurality of upper fixed seats 59 fixedly mounted on the inner cavity side wall of the washing tower body 54, the inner end of a horizontally arranged upper washing water inlet pipe 60 extends into the inner cavity of the washing tower body 54 and is fixed to the corresponding upper fixed seat 59 through a corresponding upper U-shaped clamp 61, an upper washing water inlet 62 is provided at the outer end of the upper washing water inlet pipe 60, and a plurality of upper nozzles 63 are arranged at intervals at the bottom of the middle section of the upper washing water inlet pipe 7.

[0132] The upper wash water inlet 62, the lower wash water inlet 67 and the corresponding wash water outlet 72 are matched with the corresponding circulating water pump and the heat exchanger through pipelines.

[0133] After receiving the low-temperature water flow from the external circulating water pump, the upper spray device 84 will first enter through the upper washing water inlet 62, and then due to the high pressure of the water flow, it will be continuously sprayed out from the upper nozzle 63, sprayed on the upper packing layer 81, and flow down along the surface of the packing, forming a water film on the surface of the packing. The nitrogen gas continuously passes through the gaps between the packings from bottom to top in countercurrent with the liquid, and the gas-liquid two phases are in close contact on the surface of the packing for heat and mass transfer, thereby achieving sufficient washing and cooling of the nitrogen containing impurities.

[0134] In any of the above schemes, preferably, an upper wash water replenishment port 64 is installed on the side wall of the washing tower body 54 below the upper wash water inlet 62. When the upper spray washing water is insufficient, water can be replenished into the tower through the upper wash water replenishment port 64 to ensure sufficient water supply.

[0135] In any of the above schemes, it is preferred that the lower spray device 85 includes a plurality of lower fixed seats 65 fixedly mounted on the inner cavity side wall of the washing tower body 54, an inner end of a horizontally arranged lower wash water inlet pipe 66 extends into the inner cavity of the washing tower body 54 and is fixed to the corresponding lower fixed seat 65 through a corresponding lower U-shaped clamp 80, a lower wash water inlet 67 is provided at the outer end of the lower wash water inlet pipe 66, and a plurality of lower nozzles 68 are arranged at intervals at the bottom of the middle section of the lower wash water inlet pipe 66.

[0136] After receiving the water flow from the external circulating water pump, the lower spray device 85 will first enter through the lower washing water inlet 67, and then due to the high pressure of the water flow, it will be continuously sprayed out from the lower nozzle 68, sprayed on the lower packing layer 83, and flow down along the surface of the packing, forming a water film on the surface of the packing. The nitrogen gas continuously passes through the gaps between the packings in countercurrent with the liquid from bottom to top, and the gas-liquid two phases are in close contact on the surface of the packing for heat and mass transfer, so as to fully wash and cool the nitrogen containing impurities, and cooperate with the upper spray device above to achieve better spray washing, effectively improve the washing effect and efficiency, and can quickly wash a large amount of nitrogen.

[0137] In any of the above schemes, preferably, a lower wash water replenishment port 69 is installed on the side wall of the washing tower body 54 below the lower wash water inlet 67. When the lower spray washing water is insufficient, water can be replenished into the tower through the lower wash water replenishment port 69 to ensure sufficient water supply.

[0138] In any of the above solutions, it is preferred that each of the upper nozzles 63 and each of the lower nozzles 68 is a conical spiral nozzle. The use of the conical spiral nozzle can better ensure the spraying effect and improve the adequacy of the contact between the spray washing water and the nitrogen.

[0139] In any of the above schemes, it is preferred that the upper bulk material air intake device 86 includes an upper perforated spray inclined plate 70 obliquely arranged on the inner cavity side wall of the washing tower body 54, and on the side wall of the washing tower body 54 corresponding to the upper part of the upper perforated spray inclined plate 70, a liquid level upper gauge interface 73, an overflow port 71, a wash water outlet 72, a liquid level gauge lower interface 74, and a sewage outlet 75 are installed in sequence from top to bottom, and above the upper perforated spray inclined plate 70, a plurality of vertically arranged air intake ducts 76 are spaced apart along its surface.

[0140] The upper bulk material air intake device 86 separates the upper and lower washing water to prevent the liquid from the upper spray from entering the lower spray. The gas washed by the lower spray can enter the upper spray through the vertical air intake duct 76 of the upper bulk material air intake device 86.

[0141] There is a certain amount of water in the lower part of the upper and lower sprays, so that impurities in the water can settle naturally. A liquid level meter is provided to detect the liquid level of this part of the water. When the liquid level is low, water is replenished through the water replenishment ports 64 and 69, and when the liquid level is high, excess water is discharged through the overflow port 71.

[0142] At the same time, the liquid level meter connected to the upper liquid level meter interface 73 and the lower liquid level meter interface 74 can effectively observe and measure the current water level status.

[0143] The sewage outlet 75 can discharge the dirt adhered to the upper perforated spray inclined plate 70 and the lower spray inclined plate 79 when the inside of the washing tower body 54 is cleaned after the spraying is completed.

[0144] Setting a proper tilt angle can ensure that the upper and lower sprays can drain the washing water completely.

[0145] In any of the above schemes, it is preferred that a cone tube protection cap 77 is fixedly installed on the top of each of the air intake ducts 76 , and a spacing space 78 is provided between the cone tube protection cap 77 and the top of the corresponding air intake duct 76 .

[0146] The cone tube protective cap 77 can effectively prevent the sprayed liquid from entering the air inlet duct 76, ensuring that the nitrogen gas entering can be quickly discharged from the surrounding spacing space, reducing the probability of the upper sprayed liquid entering the lower spray, and at the same time playing the role of wind uniformity.

[0147] In any of the above schemes, preferably, a lower spray inclined plate 79 is installed in the inner cavity of the washing tower body 54 below the lower spray device 85, and the incoming air enters through the air inlet 83 on the side wall of the washing tower.

[0148] In any of the above schemes, it is preferred that a packing layer 81 of a certain thickness is installed in the inner cavity of the washing tower body 1 below the upper spray device 84 .

[0149] In any of the above schemes, it is preferred that a packing layer 82 of a certain thickness is installed in the inner cavity of the washing tower body 1 below the lower spray device 85.

[0150] The nitrogen scrubber is divided into two stages, and the two stages use independent water pumps, heat exchangers and circulating water pipelines. The washing water used in the lower scrubber is cooled by circulating water. The circulating water used here can meet the requirements by passing through the cooling tower. The low-temperature washing water used in the upper scrubber is cooled by ice water. The lower scrubber washes and cools the nitrogen in one stage, and the upper scrubber further washes and cools the nitrogen to meet the air outlet requirements of the scrubber. The upper spray cools the nitrogen after the lower scrubber cools it, and the required cooling capacity is greatly reduced, so the energy consumption required for cooling capacity is greatly reduced.

[0151] In any of the above schemes, it is preferred that the feeding system adopts a metering and conveying device 10, the feed port of the metering and conveying device 10 is used to receive raw materials, and the outlet of the metering and conveying device 10 is used to communicate with the inlet end of the viscosity increasing tower 8.

[0152] The metering and conveying device 10 can be an existing product. There is no design improvement in the device here, so it will not be described in detail.

[0153] In any of the above schemes, it is preferred that the nitrogen circulation system includes a nitrogen preheater 11, the lower inlet end of the nitrogen preheater 11 is connected to the top of the thickening tower 8 and is used to receive the hot nitrogen discharged from the thickening tower 8, the upper outlet end of the nitrogen preheater 11 is connected to the inlet end of the nitrogen treatment device, the upper inlet end of the nitrogen preheater 11 is connected to the top outlet end of the nitrogen treatment device, and the lower outlet end of the nitrogen preheater 11 is connected to a multi-stage nitrogen conveying assembly, and the multi-stage nitrogen conveying assembly is used to realize the multi-path delivery of increased temperature nitrogen into the thickening tower 8.

[0154] In any of the above schemes, it is preferred that the nitrogen circulation system includes a multi-stage nitrogen delivery component, and the multi-stage nitrogen delivery component is respectively connected to the upper part, the middle part and the lower part of the viscosity increasing tower 8.

[0155] In any of the above schemes, it is preferred that the multi-stage nitrogen delivery assembly includes a plurality of groups of primary nitrogen delivery branch components, secondary nitrogen delivery branch components, and tertiary nitrogen delivery branch components arranged in parallel, and the primary nitrogen delivery branch components, the secondary nitrogen delivery branch components, and the tertiary nitrogen delivery branch components are all connected to the lower outlet end of the nitrogen preheater 11 through a main pipe.

[0156] In any of the above schemes, preferably, the primary nitrogen delivery branch component includes a primary delivery branch pipeline, on which a primary nitrogen compressor 1 and a primary heat exchanger 2 are sequentially installed in series according to the flow direction of nitrogen;

[0157] In any of the above schemes, preferably, the primary nitrogen delivery branch component includes a secondary delivery branch pipeline, on which a secondary nitrogen compressor 3 and a secondary heat exchanger 4 are sequentially installed in series according to the flow direction of nitrogen;

[0158] In any of the above schemes, it is preferred that the three-stage nitrogen delivery branch component includes a three-stage delivery branch pipeline, on which a three-stage nitrogen compressor 5, a three-stage deaerator 6, and a three-stage heat exchanger 7 are installed in series in sequence according to the flow direction of nitrogen.

[0159] In any of the above schemes, preferably, the nitrogen circulation system includes a washing tower 13, the top outlet end of the washing tower 13 is connected to the upper inlet end of the nitrogen preheater 11 through an outlet pipeline, a demister unit 12 is installed on the outlet pipeline, the lower inlet end of the washing tower 13 is connected to the upper outlet end of the nitrogen preheater 11 through a pipeline, a circulation pipeline is provided on one side of the washing tower 13, the inlet end of the circulation pipeline is connected to the bottom outlet end of the washing tower 13, the reflux end of the circulation pipeline is connected to the reflux port at the top of the washing tower 13, and a circulating water pump 14 and a circulating water heat exchanger unit are arranged in series in the circulation pipeline according to the flow direction of the circulating water.

[0160] In any of the above schemes, it is preferred that the demister unit 12 includes two demisters 1201 arranged in parallel through pipelines, and a demister opening valve 1202 is respectively provided on the branch pipelines where the two demisters 1201 are located.

[0161] The two demisters 1201 can serve as backup for each other, greatly extending the service life and use effect of the demister 1201; at the same time, even if one of them fails, the demister opening valves 1202 on both sides can be closed separately, and then it can be disassembled for maintenance, so as to realize maintenance without shutting down the whole machine, ensuring the convenience of maintenance while not affecting the normal operation of the entire system, ensuring the sustainability of equipment operation, and reducing the impact of shutdown on production.

[0162] In any of the above schemes, it is preferred that the circulating water heat exchanger unit includes two circulating water heat exchangers arranged in parallel through pipelines, and a circulation opening valve 1502 is respectively provided on the branch pipelines where the two circulating water heat exchangers are located.

[0163] The two circulating water heat exchangers can serve as backup for each other, greatly extending the service life and use effect of the circulating water heat exchangers; at the same time, even if one of them fails, the circulation opening valves 1502 on both sides can be closed separately, and then it can be disassembled for maintenance, so as to realize maintenance without shutting down the whole machine, ensuring the convenience of maintenance while not affecting the normal operation of the whole system, ensuring the sustainability of equipment operation, and reducing the impact of shutdown on production.

[0164] In any of the above schemes, it is preferred that a high-purity nitrogen gas replenishment port is provided on the pipeline between the viscosity increasing tower 8 and the demister 1201, and the high-purity nitrogen gas replenishment port can replenish the consumed nitrogen in time, effectively ensuring the continuity of the system nitrogen.

[0165] The present invention also provides a nylon chip continuous solid phase viscosity enhancement treatment method, comprising the following steps:

[0166] S1: Measuring and conveying nylon chips material and allowing the material to enter the nylon chips continuous solid phase tackifying tower 8 of the system;

[0167] S2: Nylon chips flow from top to bottom in the viscosity increasing tower 8 in a plug flow manner;

[0168] S3: nitrogen is introduced into the viscosity increasing tower 8 and is in full contact with the nylon chips;

[0169] The role of the nitrogen provided here is to take away the small molecules (water) produced as a byproduct of the viscosity increasing process.

[0170] The specific steps of introducing nitrogen in S3 are as follows: the nitrogen is divided into three streams and enters the inside of the thickening tower 8 from the upper, middle and lower parts of the thickening tower 8 respectively, and an independent nitrogen compressor and nitrogen heat exchanger are provided on each nitrogen pipeline to accurately control the flow rate and temperature of each nitrogen stream to achieve precise control of the slice temperature in the thickening tower 8. A deaerator 6 can be provided on at least one of the pipelines, and the deaerator 6 can deoxygenate the nitrogen to ensure the purity of the nitrogen.

[0171] The distribution of the internal parts in the thickening tower 8 enables the nylon particles to flow from top to bottom in a plug flow manner, ensuring that the residence time of the nylon slices in the thickening tower 8 is consistent, ultimately ensuring the uniformity of the thickening of the nylon slices, while preventing local material from not flowing and sticking.

[0172] The nylon chips are heated by three streams of nitrogen at the upper, middle and lower parts in the viscosity increasing tower 8. The temperature of the upper chips is controlled at 80-150°C, the temperature of the middle chips is controlled at 140-170°C, and the temperature of the lower chips is controlled at 160-180°C.

[0173] This system adopts nitrogen closed-loop circulation. Hot nitrogen is discharged from the top of the viscosity-increasing tower 8, enters the nitrogen preheater 11, and exchanges heat with the cold nitrogen coming out of the demister 1201. Then, it enters the washing tower 13 from the lower part of the washing tower 13. The nitrogen is washed and cooled by the washing tower 13 to remove the small molecules and water carried by the by-products of the viscosity-increasing process.

[0174] The washed nitrogen enters the demister 1201 for demisting and drying, enters the nitrogen preheater 11 for preheating, and then enters the viscosity increasing tower 8 in three streams.

[0175] The hot nitrogen entering the upper part of the thickening tower 8 is a part that has been washed, demisted and preheated by the nitrogen preheater 11. This nitrogen is pressurized by the first-stage nitrogen compressor 1 and heated by the first-stage nitrogen heat exchanger before entering the thickening tower 8 from the upper part.

[0176] The hot nitrogen entering the middle of the thickening tower 8 is a part that has been washed, demisted and preheated by the nitrogen preheater 11. This nitrogen is pressurized by the secondary nitrogen compressor 3 and heated by the secondary nitrogen heat exchanger before entering the thickening tower 8 from the middle.

[0177] The hot nitrogen entering the lower part of the thickening tower 8 is a part that has been washed, demisted and preheated by the nitrogen preheater 11. This nitrogen enters the thickening tower 8 from the lower part after being pressurized by the three-stage nitrogen compressor 5, deoxygenated by the three-stage deaerator 6 and heated by the three-stage nitrogen heat exchanger.

[0178] S4: maintaining steps S2-S3 and allowing the nylon chips to stay in the viscosity increasing tower 8 for 12 to 36 hours to complete the viscosity increasing process;

[0179] S5: After the viscosity increasing process is completed, the nylon slices after viscosity increasing in viscosity increasing tower 8 enter cooling tower 9 for cooling;

[0180] S6: Continue cooling under the cooling effect of the circulating water cooler of the cooling tower 9, and after cooling to the standard, it is sent to the finished product warehouse by pneumatic conveying.

[0181] In any of the above schemes, it is preferred that the nylon chip continuous solid phase viscosity enhancement system described in S1 is the nylon chip continuous solid phase viscosity enhancement system described in any one of claims 1 to 7.

[0182] In any of the above schemes, it is preferred that the temperature of the slices located at the upper part of the viscosity increasing tower 8 is controlled at 80-150°C, the temperature of the slices located in the middle part is controlled at 140-170°C, and the temperature of the slices located at the lower part is controlled at 160-180°C.

[0183] Specific working principle:

[0184] This system takes conventional nylon 66 chips as an example:

[0185] 1) Conventional nylon 66 chips have a particle size of Φ2.5*3.0 mm, a moisture content of 400 ppm, a chip temperature of 30°C, and a relative viscosity of 2.6. The nylon chips pass through a metering and conveying device 10 and enter a viscosity increasing tower 8.

[0186] 2) The nylon chips flow from top to bottom in the thickening tower 8 in a plug flow manner, while nitrogen is introduced in the reverse direction and fully contacts the nylon chips, and the nitrogen takes away the small molecules (water) produced as a byproduct of the thickening process.

[0187] 3) The nylon chips are heated by three streams of nitrogen in the viscosity increasing tower 8, and the temperature of the upper chips is controlled at 140°C, the temperature of the middle chips is controlled at 175°C, and the temperature of the lower chips is controlled at 180°C.

[0188] 4) The nylon chips stayed in the viscosity increasing tower 8 for 24 hours, and the viscosity of the chips increased to 3.2.

[0189] 5) After tackification in tackification tower 8, the nylon chips enter cooling tower 9. The circulating water cools the chips inside cooling tower 9 to 40°C and then pneumatically transports them to the finished product warehouse.

[0190] 6) The hot nitrogen is discharged from the top of the viscosity increasing tower 8, enters the nitrogen preheater 11, exchanges heat with the cold nitrogen coming out of the demister 1201, and then enters the washing tower 13 from the lower part of the washing tower 13. The nitrogen is washed and cooled by the washing tower 13 to remove the small molecules and water carried by the byproducts of the viscosity increasing process.

[0191] 9) The washed nitrogen enters the demister 1201 for demisting and drying, enters the nitrogen preheater 11 for preheating, and then enters the viscosity increasing tower 8 in three streams, namely the upper, middle and lower streams. A deaerator 6 is provided in the nitrogen at the lower part of the viscosity increasing tower 8. After deoxygenation by the deaerator 6, the oxygen content in the nitrogen is controlled below 10 ppm to ensure that the nylon chips are not oxidized during the viscosity increasing process.

[0192] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions described in the above embodiments can still be modified, or some or all of the technical features therein can be replaced by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and description of the present invention. For those skilled in the art, any replacement, improvement or change made to the implementation mode of the present invention falls within the protection scope of the present invention.

[0193] The matters not described in detail in the present invention are all known technologies to those skilled in the art.

Claims

1. Nylon chip continuous solid phase viscosity enhancement system, Features: It includes a feeding system, a viscosity increasing tower, a nitrogen circulation system, and a cooling tower. The downstream of the feeding system is connected to the viscosity increasing tower. The nitrogen circulation system is connected to the inside of the viscosity increasing tower and is used to transport nitrogen to the inside of the viscosity increasing tower. The viscosity increasing tower is used to continuously viscosity increase the nylon slices entering the inside. The cooling tower is connected and arranged downstream of the viscosity increasing tower and is used to cool the nylon slices after the viscosity increasing treatment. The viscosity increasing tower comprises a viscosity increasing tower body which is hollow and has a nitrogen outlet on one side of the top, an upper cone tube and a lower cone tube are respectively arranged at the top and bottom of the viscosity increasing tower body, a cone tube feed port is arranged at the top of the upper cone tube, and a cone tube discharge port is arranged at the bottom of the lower cone tube, and a plurality of first-stage air distribution and material distribution devices and second-stage air distribution and material distribution devices are alternately installed in the inner cavity of the viscosity increasing tower body from top to bottom in sequence; An upper material equalizer is provided in the inner cavity of the upper cone tube, and a lower material equalizer is provided in the inner cavity of the lower cone tube; the viscosity increasing tower body, each of the first-level air distribution equalizers, each of the second-level air distribution equalizers, the upper material equalizer, and the lower material equalizer are all coaxially arranged; The nylon particles flow from top to bottom in a plug flow manner through the combined action of the upper material distributor in the viscosity increasing tower, the first-stage air distribution material distributor and the second-stage air distribution material distributor alternately arranged in the viscosity increasing tower body, and the lower material distributor; The nitrogen circulation system comprises a multi-stage nitrogen delivery assembly, which is respectively connected to the upper part, the middle part and the lower part of the viscosity increasing tower, and at least one of the multi-stage nitrogen delivery assemblies is provided with a deaerator; The feeding system adopts a metering and conveying device, the feed port of the metering and conveying device is used to receive the raw materials, and the outlet of the metering and conveying device is used to communicate with the inlet end of the viscosity increasing tower; The first-level air distribution and material equalizer comprises a first-level material equalizing upper cone sleeve coaxially arranged with the viscosity increasing tower body, a first-level central material equalizing channel is arranged through the middle of the first-level material equalizing upper cone sleeve, an outer material equalizing channel is formed between the first-level material equalizing upper cone sleeve and the viscosity increasing tower body, and an annular first-level annular air inlet channel is arranged in the first-level material equalizing upper cone sleeve; The secondary air distribution and material equalizer includes a secondary material equalizing cone coaxially arranged with the viscosity increasing tower body, and also includes a secondary external air distribution and material equalizing inverted cone cylinder connected to the viscosity increasing tower body, a material equalizing channel is formed between the secondary external air distribution and material equalizing inverted cone cylinder and the secondary material equalizing cone, an annular secondary annular air inlet inner channel is arranged in the secondary material equalizing cone, and a secondary annular air inlet outer channel is formed between the secondary external air distribution and material equalizing inverted cone cylinder and the viscosity increasing tower body; The lower-mouth material equalizer includes a three-stage lower-mouth material equalizer, a secondary lower-mouth material equalizer, and a primary lower-mouth material equalizer coaxially arranged from top to bottom, the three-stage lower-mouth material equalizer includes a three-stage middle cone and a three-stage outer cone coaxially arranged, a three-stage inner annular lower material equalizing channel is formed between the three-stage outer cone and the three-stage middle cone, and a three-stage outer annular lower material equalizing channel is formed between the three-stage outer cone and the inner wall of the lower cone tube; the secondary lower-mouth material equalizer includes a secondary outer cone, the center of the secondary outer cone is a secondary inner annular lower material equalizing channel, and a secondary outer annular lower material equalizing channel is formed between the secondary outer cone and the inner wall of the lower cone tube; the primary lower-mouth material equalizer includes a primary middle cone, and a primary outer annular lower material equalizing channel is formed between the primary middle cone and the inner wall of the lower cone tube; The upper material equalizer includes a first-level upper material equalizer and a second-level upper material equalizer coaxially arranged from top to bottom, the first-level upper material equalizer includes a first-level upper cone coaxially and fixedly arranged inside the upper cone tube, and a first-level annular upper material equalizing channel is formed between the first-level upper cone and the inner wall of the upper cone tube; the second-level upper material equalizer includes a second-level upper inverted cone sleeve coaxially and fixedly arranged inside the upper cone tube, a second-level central upper material equalizing channel is penetrated in the middle of the second-level upper inverted cone sleeve, and a second-level outer annular upper material equalizing channel is formed between the second-level upper inverted cone sleeve and the inner wall of the upper cone tube.

2. The nylon chip continuous solid phase viscosity increasing system according to claim 1, Features: The nitrogen circulation system comprises a nitrogen preheater, the lower inlet end of the nitrogen preheater is connected to the top of the viscosity increasing tower and is used to receive the hot nitrogen discharged from the viscosity increasing tower, the upper outlet end of the nitrogen preheater is connected to the inlet end of the nitrogen treatment device, the upper inlet end of the nitrogen preheater is connected to the top outlet end of the nitrogen treatment device, and the lower outlet end of the nitrogen preheater is connected to a multi-stage nitrogen delivery assembly, and the multi-stage nitrogen delivery assembly is used to realize the delivery of nitrogen to increase the temperature in multiple ways to the viscosity increasing tower; The top angles of the three-stage lower material equalizer, the two-stage lower material equalizer and the first-stage lower material equalizer are all 30°-50°.

3. The nylon chip continuous solid phase viscosity increasing system according to claim 2, Features: The multi-stage nitrogen delivery assembly includes a plurality of groups of primary nitrogen delivery branch components, secondary nitrogen delivery branch components, and tertiary nitrogen delivery branch components arranged in parallel, and the primary nitrogen delivery branch components, the secondary nitrogen delivery branch components, and the tertiary nitrogen delivery branch components are all connected to the lower outlet end of the nitrogen preheater through a main pipe.

4. The nylon chip continuous solid phase viscosity increasing system according to claim 3, Features: The primary nitrogen delivery branch component comprises a primary delivery branch pipeline, on which a primary nitrogen compressor and a primary heat exchanger are sequentially installed in series according to the flow direction of nitrogen; The secondary nitrogen delivery branch component comprises a secondary delivery branch pipeline, on which a secondary nitrogen compressor and a secondary heat exchanger are sequentially installed in series according to the flow direction of nitrogen; The three-stage nitrogen delivery branch component includes a three-stage delivery branch pipeline, on which a three-stage nitrogen compressor, a deaerator, and a three-stage heat exchanger are sequentially installed in series according to the flow direction of nitrogen.

5. The nylon chip continuous solid phase viscosity increasing system according to claim 4, Features: The nitrogen circulation system comprises a washing tower, wherein the top outlet end of the washing tower is connected to the upper inlet end of the nitrogen preheater through an outlet pipeline, a demister unit is installed on the outlet pipeline, the lower inlet end of the washing tower is connected to the upper outlet end of the nitrogen preheater through a pipeline, a circulation pipeline is arranged on one side of the washing tower, the inlet end of the circulation pipeline is connected to the bottom outlet end of the washing tower, the reflux end of the circulation pipeline is connected to the reflux port at the top of the washing tower, and a circulation water pump and a circulation water heat exchanger unit are arranged in series in the circulation pipeline according to the flow direction of the circulation water; The washing rack is divided into two levels, and the two levels use independent water pumps, heat exchangers and circulating water pipelines. The washing water used for the lower washing is cooled by circulating water, the circulating water used for the lower washing is cooled by a cooling tower, and the low-temperature washing water for the upper washing is cooled by ice water.

6. A method for treating nylon chips by continuous solid phase viscosity enhancement, based on the nylon chips continuous solid phase viscosity enhancement system according to any one of claims 1 to 5, Features: The steps include: S1: Measuring and conveying nylon chips and allowing the materials to enter the nylon chips continuous solid phase tackifying tower of the system; S2: Nylon chips flow from top to bottom in the viscosity increasing tower in a plug flow manner; S3: nitrogen is introduced into the viscosity increasing tower and fully contacts the nylon chips, wherein the temperature of the chips at the upper part of the viscosity increasing tower is controlled at 80-150° C., the temperature of the chips at the middle part is controlled at 140-170° C., and the temperature of the chips at the lower part is controlled at 160-180° C.; S4: maintaining steps S2-S3 and allowing the nylon chips to stay in the viscosity increasing tower for 12 to 36 hours to complete the viscosity increasing process; S5: After the viscosity increasing process is completed, the nylon slices after viscosity increasing in the viscosity increasing tower enter the cooling tower for cooling; S6: Continuously cool under the cooling effect of the circulating water cooler in the cooling tower, and after cooling to the standard, it is pneumatically conveyed to the finished product warehouse.

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