CN204093433U

CN204093433U - For the production of the reactor of nylon salt solution

Info

Publication number: CN204093433U
Application number: CN201420173805.1U
Authority: CN
Inventors: 罗伯特·J·韦尔奇; 利恩·曼斯特; 保罗·诺米科斯
Original assignee: Scientific & Technical Corp Of English Weida
Current assignee: Invista North America LLC
Priority date: 2013-05-01
Filing date: 2014-04-10
Publication date: 2015-01-14
Anticipated expiration: 2024-04-10
Also published as: TWM506828U

Abstract

The reactor that disclosed is for the production of nylon salt solution.This continuous stirred tank reactor comprises entrance for dicarboxylic acid monomer, diamine monomer and optionally independent water inlet.This reactor comprises one or more baffle plate further, and comprises the shaft of impeller.This reactor also comprises temperature for adjusting nylon salt solution to prevent from being formed the recirculation circuit of slurries.Nylon salt solution is formed continuously, and after leaving continuous stirred tank reactor, to be shifted out and directly to enter holding vessel, do not add monomer further by pipeline from reactor.

Description

For the production of the reactor of nylon salt solution

the cross reference of related application

This application claims the priority of U. S. application 61/818038 enjoying in and submit on May 1st, 2013, the full content of this application and disclose incorporated herein.

Technical field

The utility model relates to the reactor for the preparation of nylon salt solution, particularly relates to the single continuous stirred tank reactor for the preparation of nylon salt solution.

Background technology

Polyamide can be used for weaving, clothes, packaging, tire enhancing, carpet, the engineering thermoplasties of molding portion of automobile, electronic equipment, sports equipment and various commercial Application usually.Nylon is a kind of high performance material, and it can be used for plastics and fiber aspect that requirement possesses excellent durability, heat resistance and toughness.The fatty polyamide being called as nylon is prepared by the salting liquid of dicarboxylic acids and diamines.Undertaken heating to make it be polymerized by after described salting liquid evaporation.A challenge in this kind of production method is exactly ensure that dicarboxylic acids and diamines have consistent mol balance in last polyamide.Such as, when producing nylon-6 by adipic acid (AA) and hexamethylene diamine (HMD), when 6, inconsistent mol balance can adversely cause molecular weight to reduce, and affects the stainability of nylon.By utilizing interval salt technique to achieve mol balance, but batch technology is not suitable for large-scale industrial production.In addition, mol balance also can be realized by multiple reactor in a continuous mode, and in the production of salt, each reactor all has independent diamines supply.

US2130947 describes a kind of such as formula H ₂nCH ₂rCH ₂nH ₂shown diamines and formula HOOCCH ₂r ' CH ₂the salting liquid of the dicarboxylic acids shown in COOH, wherein, R and R ' is that R has the chain length being at least two carbon atoms not containing olefinic and acetylene series undersaturated bivalent hydrocarbon radical.Measure the pH value of salting liquid, and determine flex point.Then described salting liquid is fed in reactor, to form polyamide.

US2012/0046439 describes the preparation method of a kind of diacid for the preparation of polyamide and diamine salts solution.The method comprises at least two kinds of diacid and the mixing of at least one diamines, wherein the weight concentration of salt is 40 ~ 70%, described method comprises: in a first step, a kind of diacid and a kind of diamines is utilized to prepare the aqueous solution of diacid and diamines, wherein the mol ratio of diacid and diamines is less than 1, and in second step, the mol ratio of adjustment diacid and diamines to 0.9-1.1, and revises the weight concentration of salt by adding another kind of acid and optionally extra water and/or diamines.

US2010/0168375 describes the salting liquid of diamines and diacid, especially the concentrated solution of hexamethylene diamine adipate, and it can be used as the parent material produced polyamide, especially produce PA66.Described solution is by mixing (wherein the weight concentration of salt is 50-80%) by diamines and diacid in a first step, to provide the aqueous solution of diacid and diamines (wherein the mol ratio of diacid/diamine is greater than 1.1), and by adding diamines, the mol ratio of diacid/diamine is adjusted to 0.9-1.1 in second step, preferred 0.99-1.01, and optionally add water wherein and prepare with the weight concentration revising salt.

US4233234 describes the method for the aqueous solution of the salt of a kind of alkane dicarboxylic acid of a continuous production 6-12 carbon atom and the alkane diamine of 6-12 carbon atom, prepares by specific alkane dicarboxylic acid and specific alkane diamine being reacted in the aqueous solution of the salt that will prepare.The aqueous solution of salt is circulated to the first mixed zone from the first mixed zone by transmission range and the second mixed zone, and liquid alkane diamines and alkane dicarboxylic acid's aqueous solution are introduced between the first mixed zone and the second mixed zone.Introduce the alkane diamine being less than equivalent, the liquid alkane diamines of surplus adds after the second mixed zone, and the aqueous solution of described salt shifts out from the first mixed zone with its speed formed.

US6995233, US6169162, US 5674794 and US3893811 all discloses polymer reactor.

Although attempted improving technique to obtain target component, as the salinity in suitable pH value, mol balance and/or nylon salt solution, but still there is challenge.Especially dicarboxylic acids, be more particularly adipic acid, it is the powder with variable particle size, thus makes bulk density change very large.Adopt dicarboxylic acid powder will introduce another variable, thus make the uniformity being difficult to realize target parameter in a continuous process, the uniformity of such as pH value and/or salinity.Volumetric feeder for dicarboxylic acid powder exacerbates this difficulty.Consider the conforming difficulty of realize target parameter in a continuous process, first prior art was dissolved before dicarboxylic acid powder is imported continuous stirred tank reactor, or used series reaction device and combine volumetric feeder and come adjust ph and salinity.Dissolved powders or use extra reactor to increase the amount of equipment, cost of investment and cost of energy.

Utility model content

In the first embodiment, the utility model relates to the reactor for the production of nylon salt solution, comprise: for the production of the continuous stirred tank reactor of nylon salt solution, it comprises: for dicarboxylic acid powder being introduced continuously the first entrance of described continuous stirred tank reactor; For the first diamines charging being introduced the second entrance of described continuous stirred tank reactor, wherein contiguous first entrance of this second entrance; Be attached to one or more baffle plates of the inwall of described continuous stirred tank reactor; Extend through the shaft at the center of described continuous stirred tank reactor, wherein this shaft comprises at least one top impeller and at least one lower impeller; And comprise the recirculation circuit of the binding site for introducing the second diamines charging in the upstream of pump and sample loop; And for nylon salt solution to be directly transferred to the pipeline of holding vessel from the recirculation circuit of continuous stirred tank reactor, wherein said pipeline is not containing any entrance for introducing other monomers, to prevent from other monomers being transferred to this pipeline or entering holding vessel, wherein, described reactor comprises single reactor; Wherein, said " other monomers " is selected from by dicarboxylic acids, diamines and its group formed.At least one lower impeller described and at least one top impeller described can comprise blade turbine respectively.At least one top impeller described can have the inclined-plane be mutually biased with the inclined-plane of at least one top impeller described.Described sample loop can comprise at least one in-line analyzer of pH value for measuring nylon salt solution and/or salinity.Described first entrance and the second entrance can be arranged in above the liquid level of continuous stirred tank reactor.Described continuous stirred tank reactor can comprise the 3rd entrance for introducing water charging.Described continuous stirred tank reactor can comprise internal heating coils further.Recirculation circuit can comprise heat exchanger, to adjust the temperature in continuous stirred tank reactor.Described continuous stirred tank reactor can comprise one or more temperature controller and one or more pressure controller, to keep temperature and the normal pressure of 60-110 DEG C.Reactor can comprise the gas port for introducing nitrogen further.Reactor can comprise the vent condenser for being back to by condensable diamines in continuous stirred tank reactor further.Continuous stirred tank reactor and pipeline can be formed by the material structure being selected from the group be made up of Hastelloy C alloys (Hastelloy C), stainless steel and other corrosion resistant materials.Continuous stirred tank reactor can keep at least 50% full liquid level.Reactor can comprise the loss in weight feeder for entering the dicarboxylic acid powder in feed pipe based on weight metering further, and dicarboxylic acid powder enters in the first entrance of continuous stirred tank reactor with the transfer of the feed rate of low variability by described feed pipe.It is front for filtering one or more filters of nylon salt solution that described pipeline can be included in holding vessel.

In second embodiment, the utility model relates to the system for the production of nylon salt solution, comprise: a) comprise hopper, feed pipe and the loss in weight feeder for the pipe that connects described hopper and described feed pipe, wherein said hopper comprises at least one for controlling the external weights measurement subsystem of supply stage and charging stage, and at least one for distributing the lower openings of dicarboxylic acid powder in the charging stage, at least one lower openings wherein said is positioned at above feed pipe; Wherein said feed pipe receives dicarboxylic acid powder and by least one rotating screw propeller, dicarboxylic acid powder is displaced through outlet; B) produce the continuous stirred tank reactor of nylon salt solution, comprising: for receiving the first entrance that the dicarboxylic acid powder entered in described continuous stirred tank reactor is connected with outlet; For diamines charging being introduced the second entrance in described continuous stirred tank reactor, wherein this second entrance is close to the first entrance; Be attached to one or more baffle plates of the inwall of described continuous stirred tank reactor; Extend through the shaft at the center of described continuous stirred tank reactor, wherein this shaft comprises at least one top impeller and at least one lower impeller; And for the temperature that adjusts the liquid in continuous stirred tank reactor to prevent the recirculation circuit forming slurries; C) for nylon salt solution directly to be entered the pipeline of holding vessel from continuous stirred tank reactor transfer, and do not have the transfer of further monomer enter this pipeline or enter accumulator tank, wherein this reactor assembly comprises single reactor.This system can comprise the supply storehouse having and to open in the supply stage and dicarboxylic acid powder is transferred to the lower valve of hopper further.This system can comprise the induction system for dicarboxylic acid powder to be transferred to hopper from supply storehouse further.Feed pipe can comprise one or more gas port for being introduced by nitrogen in dicarboxylic acid powder further.Hopper can have the top edge being less than 15 meters above system ground elevation.Pipe can comprise swinging feeder.At least one top impeller described can comprise blade turbine.At least one lower impeller described can comprise blade turbine.At least one top impeller described can have the inclined-plane be mutually biased with the inclined-plane of at least one top impeller described.This system can comprise the sample loop for measuring nylon salt solution further.First entrance and the second entrance can point to the top of continuous stirred tank reactor.Described first entrance and the second entrance can be arranged in above the liquid level of continuous stirred tank reactor.First entrance can apart from the second entrance 0.3-1m.Recirculation circuit can enter in continuous stirred tank reactor in the position of the liquid level lower than continuous stirred tank reactor.Described continuous stirred tank reactor can comprise internal heating coils further.Recirculation circuit can comprise heat exchanger, to adjust the temperature in continuous stirred tank reactor.Described continuous stirred tank reactor can comprise temperature controller and pressure controller, to keep temperature and the normal pressure of 60-110 DEG C.This system can comprise the gas port for introducing nitrogen further.Diamines charging can comprise the diamines of 20-55wt.%, such as 30-45wt.%.This system can comprise further for condensable diamines being back to outlet in continuous stirred tank reactor and recovery tower.Continuous stirred tank reactor can be constructed by corrosion resistant material and form; Wherein said " corrosion resistant material " refers to the material being selected from the group be made up of Hastelloy C alloys (Hastelloy C), stainless steel and other corrosion resistant materials.Pipeline can be formed by the material structure being selected from the group be made up of Hastelloy C alloys, stainless steel and other corrosion resistant materials.Continuous stirred tank reactor can keep at least 50% full liquid level.Continuous stirred tank reactor can have and is less than 45 minutes, is such as less than the retention time of 25 minutes.Pipeline also can have be less than 600 seconds, the retention time of such as 1-600 second.This system can comprise the loss in weight feeder for entering the dicarboxylic acid powder in feed pipe based on weight metering further, and dicarboxylic acid powder enters in the first entrance of continuous stirred tank reactor with the transfer of the feed rate of low variability by described feed pipe.Described pipeline can comprise the one or more filters for filtering nylon salt solution before holding vessel.

In the 3rd embodiment, the utility model relates to the reactor assembly for the production of nylon salt solution, comprise: the continuous stirred tank reactor producing nylon salt solution, it comprises: for adipic acid charging being introduced continuously the first entrance in described continuous stirred tank reactor; For hexamethylene diamine charging being introduced the second entrance in described continuous stirred tank reactor, wherein this second entrance is close to the first entrance; For introducing the 3rd optional entrance of water charging; Be attached to one or more baffle plates of the inwall of described continuous stirred tank reactor; Extend through the shaft at the center of described continuous stirred tank reactor, wherein this shaft comprises at least one top impeller and at least one lower impeller; And the recirculation circuit that the temperature for adjusting the liquid in continuous stirred tank reactor is starched to prevent formation; And for nylon salt solution to be directly transferred to the pipeline of holding vessel from continuous stirred tank, and not having the transfer of further monomer enter this pipeline or enter accumulator tank, wherein said reactor assembly comprises single reactor.

Accompanying drawing explanation

Below by infinite accompanying drawing, the utility model is described in further detail, wherein:

Fig. 1 is the production technology schematic diagram of the nylon salt solution of a corresponding embodiment of the present utility model;

Fig. 2 is the schematic diagram of the loss in weight feeder used in production nylon salt solution of a corresponding embodiment of the present utility model;

Fig. 3 is the schematic diagram of the single continuous stirred tank reactor used in production nylon salt solution of a corresponding embodiment of the present utility model;

Fig. 4 is the sectional view of the single continuous stirred tank reactor used in production nylon salt solution of a corresponding embodiment of the present utility model;

Fig. 5 is the schematic diagram of the nylon salt solution producing process of a corresponding embodiment of the present utility model;

Fig. 6 is the schematic diagram that the operation for nylon salt solution producing process of a corresponding embodiment of the present utility model controls;

Fig. 7 is the schematic diagram controlled for the operation with Two-stage control of nylon salt solution process of a corresponding embodiment of the present utility model;

Fig. 8 is the schematic diagram controlled for the operation with three class control of nylon salt solution process of a corresponding embodiment of the present utility model;

Fig. 9 is the schematic diagram controlled for the operation with the on-line pH value mensuration of carrying out in laboratory conditions of nylon salt solution process of a corresponding embodiment of the present utility model;

Figure 10 is the nylon-6 of a corresponding embodiment of the present utility model, the schematic diagram of 6 production technologies;

Figure 11-13 is figure of the variability of the feed rate of the adipic acid from loss in weight feeder of the corresponding embodiment of the present utility model of display.

Detailed description of the invention

Term used herein only for the object describing particular, is not intended to limit the utility model.Unless clearly shown other situation in context, singulative as used herein " " and " being somebody's turn to do " also comprise plural form.It should also be understood that, the term used in this manual " comprise " and/or " including " time describe feature described in existence, entirety, step, operation, parts and/or component, but do not hinder other features one or more, entirety, step, operation, parts group, the existence of component and/or component group or interpolation.

Such as " comprise ", " comprising ", " having ", the term of " containing " or " relating to " and variant thereof should understand widely, and comprise listed main body and equivalent, also have unlisted other main body.In addition, when " being comprised " by transitional phrases, " comprising " or " containing " when drawing component, parts group, technique or method step or any other statement, be to be understood that and also contemplate identical component, parts group, technique or method step herein, or there is other statement any of transitional phrases before the record of this component, parts group, technique or method step or other statement any " substantially by ... composition ", " by ... composition " or " being selected from by ... the group of formation ".

If applicable words, the corresponding structure in claim, material, action and the device of all functions or the equivalent of step comprise for coming any structure of n-back test, material or action in combination with the miscellaneous part of specifically stating in claim.Description of the present utility model for introduce and describe object and provide, but be not exhaustive or the utility model is restricted to disclosed form.Under the prerequisite not departing from scope and spirit of the present utility model, many changes and variant are apparent for the person of ordinary skill of the art.Here select and describe some embodiments, object carries out best explanation to principle of the present utility model and practical application, and make other those of ordinary skill of this area can understand different embodiments of the present utility model and there is multiple change, as being suitable for this special-purpose.Correspondingly, although the utility model is described according to embodiment, but those skilled in the art will recognize that, the utility model can change ground to some extent and implement within the spirit and scope of claims.

Now with detailed reference to specific disclosed theme.Although the claim cited by combination describes by disclosed theme, but is appreciated that disclosed theme is not restricted in these claims by they.On the contrary, disclosed theme covers all replacement schemes, change and equivalent, and these can be contained within the scope of disclosed theme defined by the claims.

Introduction

The utility model relates to the reactor comprising single continuous stirred tank reactor, transfer pipe and holding vessel for continuous seepage nylon salt solution.Entered single continuous stirred tank reactor with low variability feed rate formed nylon salt solution by metering dicarboxylic acid powder, in described single continuous stirred tank reactor, dicarboxylic acid powder and diamines and water react.Diamines can add with two parts.Part I is optionally combined with water, and it can be fed directly in continuous stirred tank reactor.Described continuous stirred tank reactor comprises the recirculation circuit of the tie point comprised for introducing Part II diamines.In the downstream of described tie point, described recirculation circuit comprises pump and sample loop.This reactor structure is improvements over the prior art, because employ single continuous stirred tank reactor to be formed the nylon salt solution departing from target component with low variability.By at pump and sample loop fed upstream Part II diamines, the effect adding Part II diamines can be seen in sample loop.Therefore, the uniformity of nylon salt solution is by being fed to dicarboxylic acid powder, water and two parts diamines in single continuous stirred tank reactor and obtaining.Regulate the ability of nylon salt solution to eliminate demand to extra reactor by charging Part II diamines, and therefore compared with the conventional method, decrease equipment, energy cost and fund cost.

Be applicable to the optional free ethanedioic acid of dicarboxylic acids of the present utility model, malonic acid, butanedioic acid, glutaric acid, pimelic acid, adipic acid, suberic acid, azelaic acid, decanedioic acid, heneicosanedioic acid, dodecanedioic acid, maleic acid, glutaconate, traumatic acid, muconic acid, 1, 2-or 1, 3-cyclohexyl dicarboxylic acids, 1, 2-or 1, 3-phenylenediacetic acid, 1, 2-or 1, 3-cyclohexyl oxalic acid, M-phthalic acid, terephthalic acid (TPA), 4, 4 '-oxydibenzoic acid, 4, 4-benzophenone base dicarboxylic acids, 2, 6-naphthyl dicarboxylic acids, p-tert-butyl isophthalic acid, 2, the group that 5-furans dicarboxylic acids and composition thereof is formed.In a specific embodiment, described dicarboxylic acid monomer comprises at least 80% adipic acid, as at least 95% adipic acid.

Adipic acid (AA) prepares nylon-6, and 6 dicarboxylic acids adapted to most, it uses in the form of a powder.Usually pure AA can be obtained, the impurity containing minute quantity.Typical impurity comprises other acids (monoacid and lower binary acid), nitrogenous material, trace metal (as iron (being less than 2ppm) and other heavy metals (be less than 10ppm or be less than 5ppm)), arsenic (being less than 3ppm) and the hydrocarbon ils (be less than 10ppm or be less than 5ppm) that are less than 60ppm.

Being applicable to diamines of the present utility model is selected from by ethanoldiamine, trimethylene diamine, putrescine, cadaverine, hexamethylene diamine, 2-methyl-five methylene diamine, heptamethylene diamines, 2-methyl hexamethylene diamine, 3-methyl hexamethylene diamine, 2, 2-dimethyl five methylene diamine, eight methylene diamine, 2, 5-dimethyl hexamethylene diamine, nine methylene diamine, 2, 2, 4-and 2, 4, 4-trimethyl-hexamethylene diamine, decamethylene diamine, 5-methylnonane diamines, IPD, 11 methylene diamine, ten dimethylene diamines, 2, 2, 7, 7-tetramethyl-eight methylene diamine, two (p-aminocyclohexyl) methane, two (aminomethyl) norbornane, optionally by one or more C ₁-C ₄the C that alkyl replaces ₂-C ₁₆aliphatic diamine, aliphatic poly ether diamine and furans diamines, (aminomethyl) furans as two in 2,5-, and composition thereof.The boiling point of selected diamines can higher than dicarboxylic acids, and described diamines is not preferably xylyene diamine.In a specific embodiment, described diamine monomer comprises at least 80% hexamethylene diamine, as at least 95% hexamethylene diamine.Hexamethylene diamine (HMD) is most commonly used to prepare nylon-6, and 6.HMD solidifies at about 40-42 DEG C, usually adds water to reduce its fusion temperature, makes it easily process.Therefore, concentrated solution form HMD, be the diamines of 80 ~ 100wt.% or 92 ~ 98wt.% as concentration be commercially available.

Except independent based on the polyamide of dicarboxylic acids and diamines, add other monomers and sometimes have superiority.When the ratio of adding is lower than 20wt.%, as during lower than 15wt.%, also these monomers can be joined in nylon salt solution not departing under prerequisite of the present utility model.This type of monomer can comprise monofunctional carboxylic acids, as formic acid, acetic acid, propionic acid, butyric acid, valeric acid, benzoic acid, caproic acid, enanthic acid, sad, n-nonanoic acid, capric acid, hendecanoic acid, dodecylic acid, tetradecanoic acid, tetradecenoic acid, palmitic acid, palmitoleic acid, gaidic acid (sapienic acid), stearic acid, oleic acid, elaidic acid, octadecenoic acid, linoleic acid and erucic acid etc.This type of monomer also can comprise lactams, as α-beta-lactam, α-azetidinone, azetidinone, butyrolactam, δ-valerolactam, γ-valerolactam and caprolactam etc.This type of monomer also comprises lactone, as α-second lactone, α-propiolactone, beta-propiolactone, gamma-butyrolacton, δ-valerolactone, gamma-valerolactone and caprolactone etc.This type of monomer also can comprise the alcohols of two functional groups, as mono-vinyl ethylene glycol, DIETHYLENE GLYCOL, 1,2-PD, 1, ammediol, diallyl ethylene glycol, 1,2-butanediol, 1,3-BDO, 1,4-butanediol, 2,3-butanediol, 1,2-pentanediol, 1,5-pentanediol, Rutgers 612 (etohexadiol), p-terpane-3,8-glycol, 2-methyl-2,4-pentanediol, 1,6-hexylene glycol, 1,7-heptandiol and 1,8-ethohexadiol.Also high functionality molecule can be used, as glycerine, trimethylolpropane and triethanolamine etc.Suitable hydroxylamine also alternative as monoethanolamine, diethanol amine, 3-amino-1-propyl alcohol, 1-amino-2-propyl alcohol, 4-amino-n-butyl alcohol, 3-amino-n-butyl alcohol, 2-amino-n-butyl alcohol, 4-amino-2-butanols, amylalcohol amine and hexanol amine etc.Be understandable that, under the prerequisite not departing from scope of the present utility model, also can adopt the mixture of monomer described in any one.

In polymerization technique, introduce other additives is also favourable sometimes.These additives can comprise heat stabilizer, as mantoquita, KI or any other antioxidant well known in the prior art.Examples of such additives also can comprise polymerization catalyst, as metal oxide, acid compound, containing the slaine of oxygen phosphorous compound or other compounds well known in the prior art.Examples of such additives also can be delustering agent and colouring agent, as titanium dioxide, carbon black or other pigment, dyestuff and colouring agent well known in the prior art.Additive used also can comprise defoamer, as silica dispersions, silicone copolymers or other defoamers well known in the prior art.Also lubricating auxiliary agent can be used, as zinc stearate, stearyl erucamide, stearyl alcohol, aluminium distearate, vinyl bis-stearamides or other polymeric lubricants well known in the prior art.Also nucleator can be comprised, as fumed silica or aluminium oxide, molybdenum bisuphide, talcum powder, graphite, calcirm-fluoride, phenyl-phosphonite salt or other auxiliary agents well known in the prior art in mixture.Also other known typical additives of prior art can be added in polymerization technique, as the filler of fire retardant, plasticizer, impact modifier and other types.

In the following description, term adipic acid (AA) and hexamethylene diamine (HMD) are for representing dicarboxylic acids and diamines.But the method is also for above-mentioned other dicarboxylic acids mentioned and other diamines.

The utility model obtains comprising the nylon salt solution of the AA/HMD salt with target ph easily.Especially, the utility model uses the container fewer than traditional handicraft number to obtain target ph, especially single reactor, as form nylon salt solution wherein single CSTR (CSTR) in obtain target ph.Advantageously adopt single reactor in a continuous process, the productivity ratio higher than batch technology can be obtained.In batch technology, make batch technology unrealistic for obtaining with the time quantum needed for the obtainable similar productivity ratio of continuous processing and equipment investment cost.Described target ph can be any pH value that those skilled in the art selects, and can select according to required final polymeric articles.Be not subject to theoretical constraint, target can be selected from the highest flex point of pH curve, and it is in for the scope of the polymeric articles of expection is best level.

In the embodiment that some are exemplary, the target ph of nylon salt solution can be the value between 7.200 ~ 7.900, the value preferably between 7.400 ~ 7.700.The variation of the actual pH of nylon salt solution and the target ph of nylon salt solution can lower than ± 0.04, more preferably less than ± 0.03, most preferably lower than ± 0.015.Thus, as when target ph is 7.500, so the pH value of nylon salt solution is between 7.460 ~ 7.540, more preferably between 7.470 ~ 7.530.So, such as, when target salinity is 60%, the variability of the salinity of so uniform nylon salt solution is between 59.5%-60.5%, more preferably between 59.9% ~ 60.1%.In order to realize the purpose of this utility model, the variability of pH value refers to the variation of mean rate in continued operation.This variability is very little, lower than ± 0.53%, more preferably less than ± 0.4%, obtains the nylon salt solution with homogeneous pH value.Depart from target ph uniform nylon salt solution with having low variability is conducive to the reliability improving polymerization technique, to produce uniform, high-quality polymeric articles.The nylon salt solution with homogeneous pH value also makes it possible to stabilised quality ground charging in polymerization technique.Described target ph can change according to production site.Under normal circumstances, based on free with chemically combined AA and HMD, 25 DEG C and 9.5% salinity under measure 7.620 pH value, produce and there is the nylon salt solution that AA/HMD mol ratio is 1.In order to realize the purpose of this utility model, mol ratio can change in the scope of 0.8:1.2 according to target ph.There is homogeneous pH value and also mean that the mol ratio of nylon salt solution has corresponding low variability.

Except target ph, the utility model also can reach target salinity.Target salinity can be the arbitrary salinity that those skilled in the art select, and can select according to the consideration of required final polymeric articles and storage.The water content of nylon salt solution can be between 35-50wt.%.The salinity of nylon salt solution can be 50 ~ 65wt.%, as 60 ~ 65wt.%.Nylon salt solution can lower than 110 DEG C, as 60 ~ 110 DEG C or 100-105 DEG C are preserved in fluid form under normal pressure.Concentration higher than 65wt.% needs higher temperature and pressurization may be needed to make nylon salt solution remain liquid, as homogeneous liquid.Salinity can affect storage temperature, usually can effectively store nylon salt solution at lower temperature and normal pressure.But lower salinity adversely can increase the energy ezpenditure of concentrated nylon salt solution before polymerization.

When producing nylon salt solution continuously according to the utility model, the salinity variability of nylon salt solution is preferably very low, as departed from target salinity lower than ± 0.5%, lower than ± 0.3%, lower than ± 0.2% or lower than ± 0.1%.In order to realize the purpose of this utility model, the variability of salinity refers to the variation of mean rate in continued operation.Target salinity can change according to production site.

The temperature of nylon salt solution controls independent of the mol ratio of AA and HMD.Although the mol ratio in nylon salt solution and solid concentration affect the temperature of nylon salt solution, technique relies on heat exchanger, coil pipe and/or jacket type CSTR to remove heat from technique, thus controls the concentration of nylon salt solution.The temperature of nylon salt solution can be controlled depart from temperature required lower than in the scope of ± 1 DEG C change.Can by the thermal creep stress of nylon salt solution at the boiling point lower than nylon salt solution, but higher than the crystallization temperature of nylon salt solution.Such as, solid content is the nylon salt solution boiling point at ambient pressure of 63% is 108-110 DEG C.Therefore, temperature is controlled lower than 110 DEG C, as lower than 108 DEG C, but higher than crystallization temperature.

In order to realize the low variability of nylon salt, existing technical scheme concentrates on the concentration using AA:HMD mol ratio in multiple reactor adjustment salting liquid and HMD.This be concentrated to small part be due to the bulk density of AA powder variability and difference flow behavior, result in the intrinsic unpredictability of AA powder feed.When using volumetric feeder that AA powder is fed reactor, the variability of the bulk density of AA powder is exaggerated.Due to the melt temperature that AA is high, therefore AA supplies usually in the form of a powder, thus increases the difficulty of process AA.The average grain diameter of AA powder, usually at 75 ~ 500 microns, changes in 100 ~ 300 microns.This fine powder has in fact larger surface area and more causes the particle contacts of gathering.Preferably, the particle being less than 75 microns containing being less than 20%, as being less than 10% in AA powder.Because AA powder measures based on the volume directly entered in the form of a powder in reactor usually, thus the variable effect of powder size feeds bulk packages and the density of the AA powder in nylon salt reactor.The change of these bulk packages and density and then cause the change of nylon salt pH value in solution and AA and HMD mol ratio.Consider that these change, in prior art, be provided with a series of salt reactor.For example, see US2012/0046439 and US2010/0168375.This conventional method employs the mensuration of target component, and is fed in series reaction device by monomer.But this technique needs a large amount of reactors, measurement and adjustment, thus increase cost and limit productivity ratio.In addition, compared with continuous processing, this traditional method may be more suitable for batch technology.Finally, this traditional method can not use a model to predict pH value and/or salinity, thus needs constantly to carry out adjusting to make nylon salt solution reach target component.

The effect that set forth with AA powder being fed the relevant particle size of nylon salt technique and Size Distribution is added in the prior art of AA with HMD at the multiple reactor of use.It is found that, during based on weight instead of based on volume metering AA powder, the variability of AA feed rate can reduce greatly.In certain aspects, the feed rate of AA powder can depart from target AA powder feed rate and change lower than ± 5%, as lower than ± 3% or ± 1%.By this stable charging, disclosed technique allows to use single reactor to form the nylon salt solution with target component, and does not need multiple reactors of series connection.Do not have the stable charging of AA, the variation utilizing the single reactor operated under high continuous seepage rate to be difficult to control nylon salt solution to depart from target ph and target salinity, this is limited in one's ability due to adjustment monomer.Having stable AA charging makes technology controlling and process can utilize the feed forward rate of HMD, and makes it possible to adjust supplementary HMD and carry out adjusted to ph, to reach target ph.Advantageously, desired embodiment provides a kind of disclosedly than ever more simply to design by reducing the number of the unit operations in technique.Therefore, the technique of the disclosure eliminates and thinks indispensable step in the past.Which reduce floor space and cost of investment.The nylon salt solution obtained can be polymerized further and obtain required polyamide.

In the suitability for industrialized production of nylon salt solution, for realizing acceptable production, continuous processing can be adopted to produce nylon salt solution.Batch technique needs obviously larger container and reactor.Further, batch technology is difficult to pass more small-sized continuous producing apparatus just obtainable productivity ratio.In polymerization, it is useful for originating in the nylon salt solution with homogeneous pH value and salinity.Small change can cause the product quality problems of polymerization, thus needs extra monitoring control and the adjustment of polymerization technique.

Fig. 1 provides the technique general line of the production nylon salt solution according to embodiment of the present utility model.As shown in Figure 1, nylon salt solution process 100 comprises: adipic acid is fed loss in weight feeder 110 by pipeline 102, and it produces the adipic acid charging 139 after the metering introduced in continuous stirred tank reactor 140.In addition, the water by pipeline 103 and the HMD by pipeline 104 are mixed to get the aqueous solution of HMD in static mixer 105, and it is fed in continuous stirred tank reactor 140 by pipeline 106.Liquid containing nylon salt solution is withdrawn from from reactor 140 by recirculation circuit 141, is then back to reactor 140.Be referred to herein as the extra HMD of supplementary HMD, can be joined in liquid to regulate the pH value of nylon salt at tie point 142 by pipeline 107 before analysis pH value or salinity.Nylon salt solution is withdrawn from tie point 143 and is entered pipeline 144 from recirculation circuit 141.Nylon salt solution in pipeline 144 flows through filter 190 to remove impurity, is then collected in holding vessel 195.Generally, these impurity can comprise corroding metal, and can comprise the impurity from monomer feed, as AA powder 102.Described nylon salt solution moves into polymerization process 200 by pipeline 199.Described nylon salt solution can be kept in holding vessel 195 until polymerization needs.In some embodiments, holding vessel 195 is moveable.

Nylon salt solution containment

Based on the AA powder dispenser of weight

In a specific embodiment, as shown in Figure 2, loss in weight feeder 110 is utilized to be fed in continuous stirred tank reactor 140 by AA powder 102.Loss in weight feeder 110 measures AA powder 102 to produce the AA powder feed stream 139 with low variability feed rate, and it can consider the change of the density of AA powder 102 in fill process.As mentioned above, bulk density and the flow behavior of AA powder 102 alter a great deal, thus cause the imbalance introducing mol ratio, and produce the inhomogenous pH value of nylon salt solution.Relative to can not realize AA powder low variability feed rate the feeder determining volume feeder or other types for, the utility model has advantage.For realizing the purpose of this utility model, the feed rate of the low variability of AA powder is in the scope of target feed rate ± 5% of AA powder, as in the scope of ± 3%, in the scope of ± 2% or in the scope of ± 1%.In order to realize the purpose of this utility model, the variability of feed rate refers to the variation of mean rate in continued operation.Due to the low variability of AA feed rate, the feed rate of AA is stable and measurable, therefore can use single reactor, obtains target ph and/or target salinity by the feed rate of customization diamines and water.Because AA powder feed rate departs from the low variability of target feed rate, do not need other reactor for mixing or adjustment.

Usually, loss in weight feeder 110 adds goods charging bucket 111 in supplemental stages, and at the material of charging stage distribution hopper 111.Preferably, this supplementary-charging stage circulation is enough in the time of at least 50%, and the time as at least 67% receives the feedback signal from loss in weight feeder 110.In a specific embodiment, supplemental stages accounts for the amount of total cycle time (as charging stage and total time of supplementing) can lower than 20%, as 10% lower than total cycle time or lower than total cycle time 5%.The time of supplemental stages and total cycle stage can be depending on throughput rate.In the charging stage, the material in hopper 111 is distributed to feed pipe 112, it passes through pipeline 139 by AA powder transfer in continuous stirred tank reactor 140.In addition, in supplemental stages, the AA remained in hopper 111 also can be assigned to feed pipe 112, and feed pipe 112 obtains the continuous supply of AA powder thus.Controller 113 can be used for management and control loss in weight feeder 110.Controller 113 can be and can respond dcs (DCS) or the programmable logic controller (PLC) of the input information received by output function.In a specific embodiment, multiple controller can be had for the different assemblies of system.Such as, PLC can be used for management and control supplemental stages, and DCS can be used for by setting the feed rate of targeted rate control in dcs by feed pipe 112.

As shown in Figure 2, AA powder 102 loads in supply storehouse 115 by induction system 114.Induction system 114 can be machinery or pneumatic conveyer system, is shifted out by adipic acid from loose bags, lining bulk bag, lining box container or hopper railcar depot.Mechanical conveying system can comprise spiral or haulage chain.Pneumatic conveyer system can comprise closed pipeline, utilizes forced air, AA powder 102 delivered to supply storehouse 115 by the nitrogen of evacuated air or closed-loop path.In some embodiments, induction system 114 can provide mechanical function to destroy the block of AA powder in the process loading supply storehouse 115.Supply storehouse 115 can have cylindrical shape, trapezoidal, square or other suitable moulding, has entrance 116 at its top.The moulding with the limit at band angle can help AA powder 102 to flow out from supply storehouse 115.The top edge in supply storehouse 115 can be positioned at system ground elevation 130 above lower than 20 meters of, as preferably lower than 15m.System ground elevation 130 refers to the plane of the different device stop of producing nylon salt solution, and generally defines the plane not having monomer to pass through.System ground elevation can on the entrance of CSTR.Because supply storehouse 115 is lower relative to the height of system ground elevation 130, need less energy to drive induction system 114 and to load supply storehouse 115.

Supply storehouse 115 also has lower valve 117, when lower valve 117 is closed, just defines the internal cavity preserving AA powder 102.Lower valve 117 can be rotary feeder, feeding screw, rotational flow device or the unit equipment containing feeder and valve.When filling described internal cavity with AA powder 102, lower valve 117 keeps closed condition.When supplemental stages, lower valve 117 can be opened, and based on volume, AA powder 102 is sent to hopper 111.When AA powder is sent to hopper 111 by lower valve, AA powder can be loaded into supply storehouse 115.Lower valve 117 can comprise one or more rim strip forming sealing upon closing.In one embodiment, AA powder 102 is sent to hopper 111 by conveyer belt (not shown) from supply storehouse 115.In other embodiments, supply storehouse 115 and transmit AA powder by gravity.The loading in supply storehouse 115 can independent of the loading of hopper 111.

The capacity in supply storehouse 115 can be greater than hopper 111, preferred described capacity be at least 2 times of hopper 111 or at least 3 times large.The capacity in supply storehouse 115 should be enough to the whole volume of supplementary hopper 111.The time cycle of AA powder 102 preservation in supply storehouse 115 comparablely will be grown in hopper 111, and depends on humidity concentration, and AA powder 102 can form agglomerate.Mechanical rotor or vibration (not shown) can be used to be broken by agglomerate in the bottom in supply storehouse 115.

The top edge of hopper 111 can be positioned at lower than 15m place above system ground elevation 130, as preferably lower than 12m place.Hopper 111 can have cylindrical shape, trapezoidal, square or other suitable moulding, and has entrance 118 at its top.Preferably, the inner surface of hopper is the bridging to prevent AA powder tilted.In a specific embodiment, the angle of inner surface is 30-80 °, as 40-65 °.Described inner surface can be U-type or v-shaped.Hopper 111 also can have moveable lid (not shown), lid has the hole for entrance 118 and ventilating opening.Hopper 111 can be arranged on pipe 119, and hopper 111 and feed pipe 112 couple together by it.In a specific embodiment, hopper 111 has the equivalent volume that can maintain required throughput rate.Such as, hopper 111 can have the capacity of at least 4 tons.The maximum gauge of pipe 119 is less than the maximum gauge of hopper 111.As shown, pipe 119 has rotary feeder 120 or similar conveyer, distributes to feed pipe 112 for by the material in hopper 111 by outlet 129.Rotary feeder 120 can operate opening or closing under pattern, or the speed of rotation can be controlled as the function of required feed rate.In other embodiments, pipe 119 can be free of internally feeding mechanism.Depend on the type of loss in weight feeder, available outside push-and-pull oar or the vibrator replacement swinging feeder 120 that the effluent of hopper 111 can be dispensed to feed pipe 112.Outlet 129 can have mechanical means to break AA agglomerate.In another embodiment, loss in weight feeder 110 containing drier or dry gas cleaning (not shown), to remove the moisture in AA powder, can prevent the coalescent and formation blocking in hopper 111 of AA powder.

Weight measurement subsystem 121 is connected with hopper 111.Weight measurement subsystem 121 can contain multiple sensor 122, described sensor 122 ponderable quantity hopper 111, and will show that the signal of weight is supplied to controller 113.In some embodiments, three or four sensors can be had.Sensor 122 can be connected with the outside of hopper 111, and can weigh tare weight so that hopper 111 and the initial weight being connected to any other equipment on hopper 111 to be described.In other embodiments, sensor 122 can be arranged on below hopper 111.According to the signal from weight measurement subsystem 121, controller 113 controls supplemental stages and charging stage.The weight that controller 113 more regularly measures, to determine the weight of the AA powder 102 distributing to feed pipe 112 within a period of time.Controller 113 can also control the speed of rotating screw propeller 123, described in hereafter.

In other embodiments, weight measurement subsystem 121 can be arranged under hopper 111, pipe 119 and feed pipe 112, to measure the weight of the material in these positions of loss in weight feeder 110.

Feed pipe 112 can be positioned at above pipe 119, and receives AA powder 102.In one embodiment, feed pipe 112 can be installed on pipe 119.Feed pipe 112 may extend to the plane of the outlet 129 being basically perpendicular to pipe 119, or to extend to described plane be 0-45 °, as 5-40 ° of angle, and orientating reaction device 140.Feed pipe 112 is containing at least one rotating screw propeller 123, and AA powder 102 is delivered in reactor 140 by open outlet 124 by described rotating screw propeller 123.Rotating screw propeller 123 is driven by engine 125, and can comprise screw rod.Also the configuration of twin-screw can be used.Engine 125 drives rotating screw propeller 123 with fixing or variable speed.In one embodiment, AA powder 102 is sent to reactor 140 with the feed rate of low variability by feed pipe 112.The feed rate of AA can regulate according to required throughput rate.So just allow set up fixing AA feed rate and use model described herein, then change the feed rate of other solution components to obtain required salinity and/or pH desired value.Controller 113 receives the feedback signal from loss in weight feeder 110, and adjusts the speed of rotating screw propeller 123.Controller 113 is also according to the feed rate of the signal adjustment feed pipe 112 from weight measurement subsystem 113.The command signal giving rotating screw propeller 123 affects the speed of engine, increases, maintains or reduce the speed of engine to obtain the loss in weight set.

In other embodiments, feeding line 112 as herein described can be any equivalent, controlled feeder type, as belt batcher, feeder compartment, apron feeder, oscillating feeder etc.Feed pipe 112 also can comprise damper (not shown).In addition, feeding line 112 can contain one or more gas port (not shown), for nitrogen injection to remove oxygen.

Hopper 111 also can contain high-order probe 127 and low level probe 128.Should be understood that, although for simplicity, illustrate only a high-order probe and a low level probe, multiple probe can be had.Described probe can be combined with weight measurement subsystem 121.In order to realize the utility model, described probe can be some position indicator or a capacitive proximity sensor.The position of high-order probe 127 and low level probe 128 can regulate in hopper 111.High-order probe 127 is positioned in the top close to hopper 111.When the material in hopper 111 is detected by high-order probe 127, terminate supplemental stages, and start the charging stage.Otherwise low level probe 128 is positioned at and is positioned under high-order probe 127, and closer to the bottom of hopper 111.Low level probe 128 can make to possess the enough surpluses of AA powder 102 will be assigned with in supplemental stages.When low level probe 128 detect in hopper 111 there is no material in its position time, supplemental stages starts.As mentioned above, in supplemental stages, charging can continue.

AA solid is corrosive.Loss in weight feeder 110 can by 304 of such as austenitic stainless steel _acorrosion resistant material or as 304,304L, 316 and 316L or other the material structure of the suitable corrosion resistance of the economically feasible sexual balance between equipment life and cost of investment can be provided to form.In addition, corrosion resistant material can prevent the corrosion contamination of product.Other corrosion resistant material, preferably compared with carbon steel, have higher repellence to the attack of AA.High concentration, do not have corrosivity to carbon steel as the HMD higher than 65%, therefore carbon steel can be used for storing dense HMD, and stainless steel can be used for storing the HMD compared with dilute concentration.

Although illustrate only an exemplary loss in weight feeder 110, other acceptable loss in weight feeder can comprise Acrison Models 402/404,403,405,406 and 407; Merrick Model 570; K-Tron Models KT20, T35, T60, T80, S60, S100 and S500; And BrabenderFlexWall ^tMplus and FlexWall ^tMclassic.Acceptable loss in weight feeder 110 must can reach the feed rate being enough to the running of continuous business.Such as, feed rate can be at least 500Kg/hr, as at least 1000Kg/hr, and at least 5,000Kg/hr or at least 10,000Kg/hr.Also higher feed rate can be used in embodiment of the present utility model.

reactor

In one embodiment, the utility model comprises the reactor for the production of nylon salt solution, described reactor comprises the continuous stirred tank reactor producing nylon salt solution, described continuous stirred tank reactor comprises: for dicarboxylic acid powder being introduced the first entrance of continuous stirred tank reactor, for the first diamines charging being introduced the second entrance of continuous stirred tank reactor, wherein the second entrance is adjacent with the first entrance; Be arranged at the one or more baffle plates on the inwall of CSTR; Extend through the shaft at the center of CSTR, wherein shaft comprises at least one top impeller and at least one lower impeller; And comprise the recirculation circuit of the binding site for introducing the second diamines charging in the upstream of pump and sample loop; And for nylon salt solution to be directly transferred to the pipeline of holding vessel from the recirculation circuit of continuous stirred tank, wherein said pipeline is not containing any for introducing the entrance be selected from by other monomers of dicarboxylic acids, diamines and its group be bonded, thus prevent from other monomer being transferred to this pipeline or entering holding vessel, wherein said reactor comprises single reactor.

As shown in Figure 3, nylon salt solution is prepared in single CSTR 140.Reactor 140 produces enough turbulent flows to produce the nylon salt solution of homogeneous phase.In order to realize the utility model, " CSTR " relates to a reactor, does not comprise multiple reactor.The utility model can obtain uniform nylon salt solution in single container, does not need the multiple vessel cascade as used in traditional handicraft.The continuous stirred tank reactor be suitable for is single container reactor, as the reactor of non-series connection.Advantageously, this can reduce the capital input of commercial size being produced nylon salt solution.When with loss in weight feeder described herein with the use of time, continuous stirred tank reactor can obtain the even nylon salt solution reaching target ph and target salinity.

From reactor 140, take out nylon salt solution and be directly transferred to holding vessel 195.During being fetched into from continuous stirred tank reactor 140 by nylon salt solution and entering holding vessel 195, there is no follow-up monomer A A or the introducing of HMD.More particularly, nylon salt solution is withdrawn from from recirculation circuit 141 by pipeline 144, and does not have monomer to add in pipeline 144.On the one hand, pipeline 144 is not used for the entrance introducing additional monomers, and described additional monomers can comprise dicarboxylic acids and/or diamines.Therefore, the pH value of nylon salt solution does not need further by introducing extra monomer to regulate in pipeline, especially without the need to adding extra HMD to regulate.As required, nylon salt solution can be carried out extra mixing and filtration, but as described herein, monomer only need supply single continuous stirred tank reactor.Therefore the technique of the disclosure avoids needing the sequence of multiple container and pH value in succession to measure and the step of adjustment, is considered to maintain for the manufacture of nylon 6 before it, needed for the stable stoichiometric balance between AA and HMD of 6.

Reactor 140 has between 1-6, as the ratio of height to diameter between 2-5.Reactor 140 can by be selected from by Hastelloy carbon, aluminium oxide and as 304,304L, 316 and the austenitic stainless steel of 316L and the material structure of other groups that the suitable corrosion-resistant material of economically feasible sexual balance can be provided between equipment life and cost of investment to form form.The selection of material is by considering that the temperature in continuous stirred tank reactor 140 is carried out.The time of staying in continuous stirred tank reactor 140 changes according to size and feed rate, and it is less than 45min usually, as being less than 25min.Liquid is withdrawn from outlet at bottom 148 and is entered recirculation circuit 141, and nylon salt solution is withdrawn from pipeline 144.

Usually, suitable continuous stirred tank reactor comprises at least one for introducing the monomer inlet of AA, HMD and/or water.Described entrance points to the top of reactor.In some embodiments, in monomer instillation liquid.In other embodiments, dip-tube is used in liquid level and supplies monomer.The multiple entrances for introducing each component in reaction medium can be there are.Exemplary continuous stirred tank reactor as shown in Figure 3.As shown in Figure 3, it has AA entrance 145 and HMD entrance 146.Diamines can with pure HMD or comprise 20-55wt.%, HMD and 45-80wt.% as 30-45wt.%, the water as 55-70wt.% the aqueous solution 106 form introduce.The aqueous solution 106 is introduced by entrance 146, and described entrance 146 is adjacent with the entrance 145 of dicarboxylic acid powder 139.In a specific embodiment, entrance 146 can be 0.3-1m from entrance 145.The aqueous solution 106 contributes to dissolving, and can dissolve the dicarboxylic acid powder 139 fed in reactor 140 at least partly.Water can be introduced together with diamines.Optionally, the entrance 147 for being introduced separately into water can be had.Water also can be introduced by reactor recovery tower 131.In certain aspects, recovery tower 131 is vent condenser.

Liquid in reactor 140 can be withdrawn from and continuously by recirculation circuit 141.Recirculation circuit 141 can comprise one or more pumps 149.Also temperature control equipment can be comprised, as coil pipe, chuck or containing the device of heat exchanger, temperature measuring apparatus and controller in recirculation circuit 141.Temperature control equipment can control the temperature of the nylon salt solution in recirculation circuit 141, thus prevents boiling or the oar of nylon salt solution.When extra HMD, introduced by pipeline 107 as supplementary HMD time, the tie point 142 preferably in one or more pump 149 upstream and introduce HMD in the upstream of any pH value or salinity analyzer.As what further describe herein, supplement in HMD 107 and can contain the 1-20% forming HMD needed for nylon salt solution, as the 1-10% of required HMD.Tie point 142 can be the charging aperture of recirculation circuit 141.Except making liquid recycle, pump 149 also can play the effect of secondary mixer.Pump can be used for supplementary HMD being incorporated into recirculation circuit 141 and being mixed with the liquid taken out from reactor by supplementary HMD.The group that the optional free vane pump of described pump, piston pump, flexible element pump, lobe pump, gear pump, circumference piston pump and screw pump are formed.In some embodiments, pump 149 is arranged on tie point 142 place.In other embodiments, as shown, pump 149 is arranged on the downstream of tie point 142, but before being positioned at tie point 143.After preferred secondary mixing occurs in all HMD adding and comprise by the supplementary HMD of pipeline 107, and before any analysis or taking-up enter holding vessel 195.In alternative embodiments, one or more static mixer (not shown) can be arranged in the recirculation circuit 141 in the downstream of pump 149.Exemplary static mixer is at Perry, Robert H., and Don W.Green.Perry's Chemical Engineers'Handbook.7th ed.New York:McGraw-Hill, further describe in 1997:18-25to 18-34, it is incorporated into herein by way of reference.

At tie point 143, nylon salt solution is withdrawn from pipeline 144.The time of staying in pipeline 144 can change according to the position of holding vessel 195 and filter 190, is usually less than 600 seconds, as lower than 400 seconds.In one embodiment, valve 150 is for controlling the pressure of nylon salt solution.Although illustrate only a valve, be construed as and can use extra valve in recirculation circuit 141.Do not have in the downstream of tie point 143 monomer such as AA or HMD to introduce, or do not have monomer such as AA or HMD to join in pipeline 144.In addition, monomer is not had to be incorporated in holding vessel 195 under normal handling conditions.

Recirculation circuit 141 also can comprise the heat exchanger 151 for regulating the fluid temperature in reactor 140.Temperature is positioned at the temperature controller (not shown) that reactor 140 or continuous stirred tank reactor 140 export (not shown) regulates by using.The temperature of liquid can utilize inner heat exchanger, as coil pipe or jacketed reactor (not shown) regulate.Heat exchanger 151 can supply the cooling water maintaining more than the freezing point of the salt of given concentration.In one embodiment, heat exchanger can be indirectly shell-and-tube exchanger, spirality or plate and frame heat exchanger, or for the reboiler of the recovery heat of carrying out autoreactor 140.Temperature in reactor 140 maintains in the scope of 60-110 DEG C, in case grouting liquid is formed and crystallization is formed.When water content increases, the temperature maintained needed for solution declines.In addition, the temperature in reactor 140 maintains low temperature to prevent the oxidation of HMD.Also blanket of nitrogen can be provided to prevent the oxidation of HMD.

As shown in Figure 3, in a specific embodiment, reactor 140 has inner coil pipe 152, feeds cooling agent be in the scope of 60-110 DEG C to regulate the temperature of reactor to described inner coil pipe 152.In another specific embodiment, reactor 140 also can have the chuck (not shown) with cooling agent.The heat that inner coil pipe also produces by reclaiming reaction regulates temperature.

Except temperature controller, reactor 140 also can have atmospheric exhaust mouth with vent condenser to maintain the atmospheric pressure in reactor 140.Pressure controller can containing inner and/or outside pressure sensor.

In a specific embodiment, also can have sample line 153, for measuring pH value and/or the salinity of nylon salt.Can there is fluid communication with recirculation circuit 141 in sample line 153, and preferably therefrom receive fixing flowing flowing to be minimized the impact of analyzer.On the one hand, sample line 153 can withdraw from be less than 1%, the nylon salt solution being arranged in recirculation circuit 141 more preferably less than 0.5%.One or more analyzer 154 can be had at sample line 153.In some embodiments, sample line 153 can comprise filter (not shown).In another embodiment, sample line 153 can comprise suitable heating or cooling device, if heat exchanger is with the temperature of adjustment and Quality control stream.Similarly, sample line 153 can comprise the water charge line (not shown) for adding water to regulate concentration in sample stream.If add water in sample stream, then water can be deionized water.Calculate the water that provided by sample line 153 to maintain target salinity, and other water charging of adjustable.Analyzer 154 can comprise the in-line analyzer for measuring in real time.According to the type of sampling, the part of testing is back in reactor 140 by pipeline 155 or emits.Sample line 153 returns by recirculation circuit 141.Alternatively, sample line 153 can be back to reactor 140 in independent position.

Continuous stirred tank reactor 140 keeps at least 50% completely, as at least 60% full liquid level.Select described liquid level to make nylon salt solution can the oar of submergence CSTR, thus prevent nylon salt solution from forming foam.Nitrogen or other inert gases are incorporated into liquid level 156 superjacent air space by pore 157.

The inside of continuous stirred tank reactor 140 can provide enough mixing to obtain having the nylon salt solution of homogeneous pH value.As shown in Figure 4, existence extends perpendicularly to reactor 140 and passes the shaft 159 at the center of reactor 140.Preferably, shaft 158 extends along the center line of reactor 140, but in certain embodiments, shaft 158 can pass center.In optional embodiment, shaft can be what tilt.Reach required stirring as long as can cross, also can use eccentric shaft.

Shaft 158 can contain one or more impeller 159, as paddle, hurricane band, anchor, spiral, screw and/or turbine type.Preferred aial flow impeller is for mixing AA and HMD, and this is because this kind of impeller trend prevents solid particle in the bottom sedimentation of reactor 140.In other embodiments, impeller can be flat oar radial turbine, and it has the several equidistant blade around disk.Can 2-10 impeller be contained, as 2-4 impeller at whole shaft 158.Blade 160 on impeller 159 can be straight, curved formula, female, male, angled or oblique.The number of blade 160 can 2-20, as 2-10 between change.If necessary, blade 160 also can have balancer (not shown) or scraper (not shown).

As shown in Figure 4, which show three inclination turbine assemblings 161.Shaft 158 comprises oblique leaf turbine 162 and the oblique leaf turbine 163 at least one bottom at least one top.In three inclination turbine assemblings 161, the inclined-plane 164 of preferred top oblique leaf turbine 162 is biased mutually with the inclined-plane 164 ' of the oblique leaf turbine 163 in bottom.

Also the multiple shaft with dissimilar impeller can be used, as auger axle and anchor formula shaft.Side mounted shaft can also be used, especially marine propeller.

Be back to Fig. 3, shaft 158 is driven by outer 165, and it can at 50-500rpm, as the speed mixing material of 50-300rpm.Shaft 158 is removably mounted on motor driven axle 166 at connector 167 place.The speed variable of motion, but under normal circumstances, the whole surface area that described speed sufficiently maintains solid particle contacts with liquid phase, thus the maximum availability that guarantee interfacial area is transmitted for the quality of solid-liquid.

Reactor 140 also can comprise one or more baffle plate 168, for mixing and preventing dead angle from being formed.The number of baffle plate 168 at 2-20, as changed in the scope of 2-10, and can be evenly distributed on the periphery of reactor 140.Baffle plate 168 can be arranged on the inwall of reactor 140.Usual use vertical baffle, but also can use curved baffle.Baffle plate 168 may extend to higher than the liquid level 156 in reactor 140.

In one embodiment, reactor 140 comprises the exhaust outlet for being removed tail gas by pipeline 135 and the recovery tower 131 for compressible HMD being back to reactor 140.Water 132 by infeed recovery tower 131, and can be recovered in the bottom 133 of recovery tower 131.Water 132 feeds with minimum speed with the efficiency maintaining recovery tower 131.Calculate the water yield to maintain target salinity, and other water charging adjustable.Discharge gas 134 can be condensed to reclaim any water and monomer tail gas, and pipeline 133 can be back to.The gas comprising the incoagulability of nitrogen and air can be removed as tail gas stream 135.When recovery tower 131 is vent condenser, recovery tower 131 can be used for reclaiming tail gas and removing incoagulable gas.

The storage of nylon salt solution

As shown in Figure 3, after nylon salt solution is formed, it is supplied into holding vessel 195, and described nylon salt solution can be stored in holding vessel 195 until polymerization needs.In some embodiments, holding vessel 195 can comprise recirculation circuit 193, in order to the nylon salt solution that circulates.Internal spray blender 194 can be used to maintain the circulation in holding vessel 195.In a specific embodiment, internal spray blender 194 can be arranged on 0.3-1.5m place bottom distance holding vessel 195, preferred 0.5-1m place.In addition, in some embodiments, at least part of nylon salt solution can be back in reactor 140, freezes and/or the adjustment nylon salt solution when system perturbations or target ph and/or target salting liquid need change to prevent process pipelines.Any untapped nylon salt solution from polymerization technique 200 also can be back to holding vessel 195.

Holding vessel 195 can by being selected from by austenitic stainless steel, and as 304,304L, 316 and 316L, or the material structure of other groups that the suitable corrosion-resistant material of economically feasible sexual balance can be provided between equipment life and cost of investment to form forms.According to the size of holding vessel and the volume of nylon salt solution to be stored, holding vessel 195 can comprise one or more holding vessel.In some embodiments, nylon salt solution is stored at least two holding vessels, as at least 3 holding vessels, at least 4 holding vessels or at least 5 holding vessels.Holding vessel 195 can be maintained at the temperature higher than solution freezing point, as between 60-110 DEG C.Salinity due to nylon salt solution is 60-65wt.%, and therefore temperature can remain between 100-110 DEG C.Interior heater 196 can be had in holding vessel.In addition, recirculation circuit can contain one or more heater 197, for providing heat to holding vessel.Such as, holding vessel can have the capacity holding and reach 5 days stocks, more preferably reach the nylon salt solution of 3 days stocks.Holding vessel can keep normal pressure or be slightly higher than normal pressure in blanket of nitrogen.

In some embodiments, before entering holding vessel 195, nylon salt solution can carry out filtering to remove impurity.Nylon salt solution by least one filter 190, as at least two filters or at least three filters filter.Filter 190 can be in parallel or be arranged in series.Suitable filter can comprise the membrane filter containing polypropylene, cellulose, cotton and/or glass fibre.In some embodiments, the aperture of filter is between 1-20 micron, between 2-10 micron.Described filter also can be ultra filtration filter, Microfiltration Unit, nanofiltration filter or active carbon filter.

supplement HMD

Described in above, HMD two positions in the process forming nylon salt solution used add different parts, main HMD and supplementary HMD.In order to allow to use single continuous stirred tank reactor and form homogeneous nylon salt solution, entering pipeline 144 once nylon salt solution is taken out from reactor 140 and entering holding vessel 165 subsequently, then not adding HMD.Depart from target component such as the control of the difference of target ph to come further accurately via the supplementary HMD of pipeline 107 at tie point 142 place as shown in Figure 5 by comprising.The minimum part of the HMD that supplementary HMD is normally added, as the trickle adjustment of nylon salt solution ph, this is owing to comparing with main HMD charging, using less valve can control the minor variations of flow better.Due to the adjustment of main HMD and pH value measure between delay, less preferred employing adjusts the feed rate of main HMD or the method for flow rate to control the pH value of nylon salt solution.In addition, because supplementary HMD is the minimum part of the HMD joining CSTR, supplementary HMD makes it possible to the pH value adjusting nylon salt solution more accurately, and pH analyzer provides nearprompt feedback.Supplement the upstream that measures at pH of HMD to add, with reduce measurement add supplementary diamines pH value affected in delay.When adjusting supplementary HMD, water feed rate also can be adjusted to control the solid concentration in nylon salt solution.As described herein, the setting of this adjustment available controller refractometer in available samples pipeline 153 are monitored.

Supplement HMD 107 to mix with nylon salt solution before it enters pipeline 144.Although there is no theoretical constraint, can think that supplementary HMD 107 can react with any remaining free AA in nylon salt solution.In addition, as mentioned above, the pH value that supplementary HMD 107 can be used for adjusting nylon salt solution is added.

In one embodiment, the utility model relates to based on the AA powder of weight metering from loss in weight feeder 110 to feed pipe, and the AA powder feed 139 of metering is transferred in continuous stirred tank reactor 140 with the charging rate of low variability by described feed pipe; Individually the aqueous solution 106 comprising Part I HMD104 and water 103 is incorporated in continuous stirred tank reactor 140 and forms nylon salt solution; And by pipeline 107 by Part II HMD, such as, supplement HMD and be incorporated in nylon salt solution.At tie point 142 supplementary HMD 107 can be joined in the nylon salt solution in recirculation circuit 141.Supplementing HMD 107 is constantly added in recirculation circuit 141 with certain feed rate, and described certain feed rate can make the flow of supplementary HMD 107 be middle-grade flow by valve, as 20-60%, 40-50%, or about 50%.Middle-grade flow refers to and remains out of hand to prevent by the continuous flow of valve.

For obtaining the target ph with low variability, described technique comprises the constant feed rate utilizing loss in weight feeder 110 to provide AA powder 102, and the feed rate of adjustment HMD and water controls with response technique.Advantageously, from continuous processing, high production rate is obtained.When changing salt throughput rate, because AA feed rate changes within the discrete time interval, HMD feed rate can adjust pro rata.The feed rate of HMD can be regulated by the feed rate of the feed rate or supplementary HMD that change main HMD charging.In a preferred embodiment, for given salt throughput rate, the feed rate of supplementary HMD 107 can be regulated, and the feed rate of the feed rate of HMD 104 or HMD aqueous solution charging 106 can be constant.In alternative embodiments, if necessary, the feed rate of supplementing HMD 107 can be set as constant speed, and the feed rate of the feed rate of adjustable HMD 104 or HMD aqueous solution charging 106 is to reach target ph and/or target salinity.In some other embodiment, the feed rate of adjustable HMD 104 and supplementary HMD 107 or the feed rate of the HMD aqueous solution 106 are to reach target ph and/or salinity.

Supplementary HMD 107 can have identical HMD with HMD 104 and originate.HMD 104 can comprise the 80-99% of total HMD in nylon salt solution, as 90-99%.Supplement the 1-20% that HMD 107 can comprise total HMD in nylon salt solution, as 1-10%.The ratio of HMD 104 and supplementary HMD 107 can regulate according to target ph and target salinity.As discussed herein, the ratio of HMD 104 and supplementary HMD 107 is by the model specification for total HMD feed rate.

HMD can with the form supply of pure HMD, as containing at least 99.5wt.%HMD, as anhydrous in 100%HMD, or with the form supply of the aqueous solution containing 80-99.5wt.%HMD.Supplement HMD 107 and can be fed into nylon salt solution with the form of pure HMD or the HMD aqueous solution.When supplementary HMD 107 is the HMD aqueous solution, supplement the HMD that the aqueous solution of HMD 107 can comprise 50-99wt.%, as the HMD of at least 60-95wt.% or 70-90wt.%.When this aqueous solution is used for HMD 104, the amount of water can regulate based on the target salinity of the source of HMD and nylon salt solution.Advantageously, supplementing the HMD concentration of HMD107 is 90-100wt.%, thus the impact making supplementary HMD 107 control salinity is minimized while, improves its impact on pH value control.

Supplement HMD 107 to join in the nylon salt solution in recirculation circuit in the upstream of pump 149 and sample line 153.After adding supplementary HMD 107, on sample line 153, the pH value of nylon salt solution in recirculation circuit 141 can be measured with analyzer 154.This just makes there is little delay between the feed rate adjust ph and pH value by supplementing HMD 107 measures.Extra AA is not had to join in recirculation circuit 141.Except supplementary HMD 107, HMD is not had to join in recirculation circuit 141.The upstream that supplementary HMD 107 measures in pH value adds, and measures to allow the pH value comprising supplementary HMD.

Be different from the existing technique shown in US2010-0168375 and US4233234, supplement HMD and do not add after pH value measures.After pH value measures, add membership cause and measuring the HMD that adds to the large delay in the impact of pH value, this is that HMD owing to adding has to flow through reactor before determined.Thus, add by this way HMD can lower than or exceed target ph, this will cause these technique to be run inefficiently by constantly pursuing of goal pH value.Advantageously, the utility model adds supplementary HMD in the upstream that pH value measures, thus makes the impact of supplementary HMD only cause little delay, and avoids the problem below or above target ph.In addition, because valve maintains middle-grade flow, in the utility model, constantly add supplementary HMD 107.

technology controlling and process

As described herein, in prior art processes for generation of in polyamide salt solution, continuous processing as nylon salt solution, the target component in nylon salt solution, comprises pH value and salinity, has variability.This variability of target component can be caused by AA powder feed rate that is uncertain and fluctuation at least partly.This unpredictability and fluctuation make technique be difficult to control, this is because this technique must constantly be monitored in the downstream of initial reactor, before storage and regulate.Thus, the single reactor run continuously is difficult to effectively overcome this uncertain AA powder feed rate with fluctuating.Traditionally, in order to overcome this unpredictability and fluctuation, the position adopting several reactor, blender and multiple monomer feed locations especially to add HMD produces the nylon salt solution with target component.According to the utility model, single continuous stirred tank reactor is adopted to remove the ability of the nylon salt solution in the several reactor of adjustment.But, by the unpredictability and the fluctuation that use loss in weight feeder to reduce AA powder feed rate, can obtain changing the AA powder feed rate lower than ± 5%, the utility model can utilize the feedforward control based on model, in conjunction with or not in conjunction with feedback information, to obtain the nylon salt solution with target ph and target salinity.

feedforward control

Between the continuous processing producing nylon salt solution starts, reaction model can be set up based on the productivity ratio of required nylon salt solution.Based on described productivity ratio, setting AA powder feed rate, pH value of then setting objectives and target salinity.Then HMD feed rate and water feed rate is calculated to reach target ph and target salinity by stoichiometric proportion.HMD feed rate comprises main HMD and supplementary HMD.Water feed rate comprises the water in all sources feeding reactor 140.It should be understood that the target mol ratio of target ph reflection AA and HMD.In further embodiment, extra feature can join in described model, includes but not limited to reaction temperature and reaction pressure.The feed rate of HMD and/or water that this model is used for for entering continuous stirred tank reactor arranges feedforward control.

In some embodiments, the feed rate by inputting the AA powder provided by described loss in weight feeder herein sets up model.For a given productivity ratio, the feed rate of AA should be constant.As described herein, loss in weight feeder can comprise discrete control to produce the AA powder feed rate with low variability.From loss in weight feeder AA powder feed rate serially, semi-continuously or in Discrete time intervals, as model as described in being supplied to for every 5 minutes, every 30 minutes or per hour.In other respects, due to the low variability of AA powder feed rate, once AA powder feed rate is set, then described model can set the feed rate of HMD and the feed rate of water.These feed rates pass through described model specification, to obtain target ph and target salinity.

Described model can be dynamic, and can regulate according to from feedback signal that is online or off-line type analyzer.Such as, if need to change productivity ratio, pH value and salinity, can adjust model.Described model can be kept in the memory of controller, as programmable logic controller (PLC) (PLC) controller, dcs (DCS) controller or proportional-integral-differential (PID) controller.In one embodiment, the PID controller with feedback signal can be used for the error in model calculating and flow measurement is described.

Owing to using volumetric feeder can not the feed rate of Accurate Prediction AA powder, complete to form by feedforward control the nylon salt solution departing from target component low rate of change be unpractical before.This is the change due to the AA powder feed rate using volumetric feeder to cause at least partially.Due to the variability of AA powder feed, cannot Modling model for the ratio of control AA and HMD.Therefore, these traditional handicrafts can use FEEDBACK CONTROL, thus need to adjust continually or are batch technology.But when entering the AA powder of continuous stirred tank reactor based on weight metering, feedforward control is just enough to continuous seepage departs from target component nylon salt solution with low rate of change.

Thus, in one embodiment, the utility model relates to one for controlling the technique of the continuous production of nylon salt solution, comprising: the model generating the target feed rate for setting dicarboxylic acid powder, to produce the nylon salt solution with target ph; Based on weight, measure the dicarboxylic acid powder from loss in weight feeder to feed pipe, thus control the variability of dicarboxylic acid powder feed rate, dicarboxylic acid powder is transferred in single continuous stirred tank reactor with target feed rate by described feed pipe; Introduce in single continuous stirred tank reactor by diamines and water with the first feed rate and the second feed rate respectively, wherein the first feed rate and/or the second feed rate are based on model; And nylon salt solution taken out continuously from single continuous stirred tank reactor directly send into holding vessel, the pH value of the nylon salt solution wherein taken out and the deviation value of target pH are lower than ± 0.04.

In order to further illustrate according to process control schemes of the present utility model, as Fig. 6 shows schematic diagram.In order to simplify, in Fig. 6, do not show multiple pump, recirculation circuit and heater.Show the many flowmeters for the flow in measuring system in figure 6, as coriolis mass flowmeters, positive displacement flow meter, electromagnetic flowmeter and turbine flowmeter etc.In some embodiments, flowmeter also can measuring tempeature and/or density.The output signal of flowmeter is input in controller 113 serially or termly.Preferably, at least one flowmeter is all had in the upstream of each flowmeter valve.In some embodiments, these flowmeters and flowmeter valve can be overall, and provide together with the form of compact apparatus.Although illustrate only a controller, in some embodiments, multiple controller can be had.As shown in Figure 6, AA powder feeds in loss in weight feeder 110 by pipeline 102, to produce the AA powder feed 139 of metering.Signal 211 is delivered to rotating screw propeller 123 by controller 113.Signal can be wireless signal.Utilize model, the feedforward feed rate model of HMD and water can be stored in controller 113.As mentioned above, loss in weight feeder 110 regulates the variability of AA powder, thus the AA powder feed 139 providing low variability to depart from the metering of target feed rate.Such as, loss in weight feeder 110 can use the backfeed loop from weight measurement subsystem 121, to regulate the speed of rotating screw propeller 123.

Controller 113 sends feed-forward signal 213 to flowmeter valve 214 to regulate the flow of the water 103 being entered reactor 140 by pipeline 106.Similarly, controller 113 is sent feed-forward signal 215 to flowmeter valve 216 and regulates the flow of the HMD 104 being entered reactor 140 by pipeline 106.These feed-forward signals by model specification to reach target ph and target salinity.In another embodiment, controller 113 sends feed-forward signal (not shown) to flowmeter valve (not shown) to regulate the feed rate entering the HMD aqueous solution 106 of reactor 140.Because feed-forward signal 213 and 215 is for entering HMD and the water of reactor 140, it is not required for therefore carrying out that online or off-line type measures to the HMD aqueous solution 106.In addition, there is the feed-forward signal 217 flowing to flowmeter valve 218, to regulate the flow of the supplementary HMD107 entering recirculation circuit 141.Model can determine the relative quantity of the HMD charging by main HMD and supplementary HMD.Regulate feed-forward signal 217 to ensure that the flowmeter valve 217 of supplementary HMD is middle-grade output flow.In one embodiment, model can set up feed rate, and it reaches flow measurement valve 218 by feed-forward control signals 217, to ensure to maintain the constant flow from supplementary HMD 107, i.e. middle-grade flow.

secondary process controls

Except using feedforward control based on modeling as shown in Figure 6, technology controlling and process can comprise feedback signal and control as secondary process, to obtain target ph and target salinity.These feedback signals can be from for adjusting HMD and water charging, especially supplement HMD and the flowmeter of water charging and the measured value of in-line analyzer 154.In-line analyzer 154 can comprise pH probe, refractometer and its combination.These pH probes and refractometer can in parallel or series connection.

As described herein, when based on weight metering AA powder, the feed rate of AA powder has low variability.This low variability provides reliable AA powder feed rate, improves the ability reaching target ph and target salinity and the ability regulating HMD and water feed rate based on feedback signal.Therefore, in a specific embodiment, the utility model relates to one for controlling the technique of the continuous production of nylon salt solution, comprising: the model generating the target feed rate for setting dicarboxylic acid powder, to produce the nylon salt solution with target ph; Based on weight, measure the dicarboxylic acid powder from loss in weight feeder to feed pipe, thus control the variability of dicarboxylic acid powder feed rate, dicarboxylic acid powder is transferred in single continuous stirred tank reactor with target feed rate by described feed pipe; And respectively diamines and water are introduced single continuous stirred tank reactor with the first feed rate and the second feed rate, to produce the nylon salt solution with target ph; With the 3rd feed rate, supplementary diamines is incorporated in the recirculation circuit of single continuous stirred tank reactor continuously; Introduce the downstream supplementing diamines, utilize the change of the pH value of the online pH measured value monitoring nylon salt solution of nylon salt solution; Adjust the 3rd feed rate to respond the change of pH value, with produce pH value depart from target pH lower than ± 0.04 nylon salt solution.

As shown in Figure 7, the online analyzer of technology utilization 154, produce feedback signal, to measure the pH value of the nylon salt solution in recirculation circuit 141 as online pH meter 154.In order to be conducive to the on-line measurement of the pH value of nylon solution, nylon salt solution is taken out continuously from reactor, and recirculation circuit 141 and sample line 153 will be imported by nylon salt solution at least partially.Recirculation circuit 141 can comprise flowmeter (not shown) and flowmeter valve.In another specific embodiment, recirculation circuit 141 can comprise pressure controller (not shown), to control the flowing of nylon salt solution.Preferably, the flow flowing through the nylon salt solution of recirculation circuit 141 is constant.Sample line 153 comprises device that the device that measures for pH value measures as pH meter and/or salinity as refractometer.In a specific embodiment, the pH value of nylon salt solution is measured under reactor condition at least partially, without any dilution or cooling.Then this nylon salt solution is directly or be back to reactor 140 by vent condenser 131 at least partially.When nylon salt solution is back to reactor by vent condenser 131 at least partially for this, nylon salt solution can replace the water feeding vent condenser.Sample line 153 also can comprise the cooler (not shown) for cooling nylon salt solution before measuring pH value and the temperature sensor (not shown) for measuring temperature before measuring pH value.In some specific embodiments, before pH value determination, nylon salt solution is cooled to target temperature.This target temperature can in the target zone than low 5-10 DEG C of the nylon salt solution existed in reactor 140.This temperature can depart from target temperature lower than ± 1 DEG C, as changed lower than ± 0.5 DEG C.Temperature sensor (not shown) can be had, to monitor the temperature measuring the nylon salt solution of upstream at pH.

Then online pH meter 154 provides output signal 226 to controller 113.The pH value that online pH meter records is passed to controller 113 by this output signal 226.Online pH meter is for measuring the change of the pH value of nylon salt solution in a continuous process.In other words, due to the condition of change, online pH meter can measure pH value that can be different from target ph, but when the pH value measured changes, controller 113 adjusts the charging of monomer.In preferred embodiments, the change of the pH value of nylon salt solution lower than ± 0.04, as lower than ± 0.03 or lower than ± 0.015.Due to the skew of online pH meter measured value, online pH meter is for measuring the variability of pH but not pH absolute value.This ascribes the feedforward control that can set target ph at least in part to.If pH value changes, by using online pH meter to measure, the change in production technology can be detected.Adopt Two-stage control, the change of pH value can cause the corresponding adjustment of at least one sent into respectively by holding wire 215 and 217 in the feed rate of flowmeter valve 216 and 218.For providing sensitive pH value to regulate, by line 217, signal is delivered to valve 218 to adjust supplementary HMD 107.The adjustment amount made supplementary HMD 107 is by taking in the corresponding change that main HMD 104 makes through flowmeter valve 216.This adjustment is response, once not show pH value change, it should be able to be recovered to the feed rate of feedforward control setting.Also the salinity of nylon salt solution can be affected on the adjustment of supplementary HMD 107.The change of this kind of salinity is adjusted by signal 213 and is controlled by the water of flowmeter valve 214.

Because the described technique for the formation of nylon salt solution is continuous print, the pH measured value in online pH meter 154 can in real time (as continuously) or closely obtain in real time.In some embodiments, pH value measures every 60 minutes, as every 45 minutes, every 30 minutes, every 15 minutes or every 5 minutes carry out.The accuracy of pH meter is in ± 0.05 scope, as in ± 0.02 scope.

Except online pH meter 154, described technique can comprise the salinity utilizing refractometer to measure nylon salt solution further, and adjustment water feed rate.In one embodiment, the water by feeding recovery tower 131 regulates the feed rate of water.Salinity by adding or removing water to regulate in the nylon salt solution of reactor downstream.

According to based on feedback needed for adjustment, model also can use Two-stage control to adjust main HMD and water.When pH tends to the long-run adjustment causing supplementary HMD 107, this control is particularly favourable.

Except the feedback information from online pH meter 154, every flow meters provides information or quality feed rate can to controller 113.As shown in Figure 7, every flow meters valve is all connected with flowmeter, and described flowmeter preferably can measurement quality flow.Flowmeter 214 ' provides information by pipeline 213 ' to controller 113.Flowmeter 216 ' provides feedback information by pipeline 215 ' to controller 113.Flowmeter 218 ' provides feedback information by pipeline 217 ' to controller 113.From the Information Availability of flowmeter in maintaining total feed rate.

The existing technique of the pH value of pH probe measurement nylon salt solution is utilized to be disclosed.See US4233234 and US2010/0168375.But each these existing technique all measures the pH value of nylon salt solution, then add extra diamines and/or acid carrys out adjusted to ph.Extra diamines and/or the effect of diacid are until extra diamines and/or diacid are mixed into reactor and withdraw from from reactor again carries out mensuration and can determine.PH value that the method causes " chasing ", and cause and can to exceed or lower than insensitive technology controlling and process of target ph.

In the utility model, as Fig. 3,5,6,7, shown in 8 and 9, supplement HMD 107 and preferably add in the upstream of online pH meter.Thus, the HMD supplemented in HMD 107 mixes with nylon salt solution, and is recycled the pH value of the pre-test nylon salt solution by reactor 140 at it in reactor recirculation circuit.

There is the secondary process measured online experiment room control

As mentioned above, the pH value controlled from secondary process is measured and must not be reflected target ph, but for illustration of the change of pH value.In order to improve the sensitiveness that pH value measures, secondary process controls also to relate to the pH value measuring nylon salt solution under laboratory controls.Although be not bound by theory, due to the sensitiveness that the pH value that improve nearly yield point place under the concentration reduced and temperature conditions is measured, the pH value therefore measuring nylon salt solution under laboratory controls improves the accuracy of measurement.This can make it possible to detect may note at reaction conditions less than the change of little pH.In order to realize the purpose of this utility model, laboratory condition refers at 15-40 DEG C, as 20-35 DEG C or measure nylon salt solution example at the temperature of 25 ± 0.2 DEG C.The nylon salt solution example measured in laboratory conditions has 8-12%, as the salinity of 9.5%.The mensuration of pH value is in laboratory conditions carried out online by the nylon salt solution in dilution and cooling sample line 153.

Therefore, in one embodiment, the utility model relates to one for controlling the technique of the continuous production of nylon salt solution, comprising: the target feed rate generated for setting dicarboxylic acid powder has the model of the nylon salt solution of target ph with generation; Based on weight, measure the dicarboxylic acid powder from loss in weight feeder to feed pipe, thus control the variability of dicarboxylic acid powder feed rate, dicarboxylic acid powder is transferred in single continuous stirred tank reactor with target feed rate by described feed pipe; And respectively diamines and water are introduced in single continuous stirred tank reactor with the first feed rate and the second feed rate, to produce the nylon salt solution with target ph; With the 3rd feed rate, supplementary diamines is incorporated in the recirculation circuit of single continuous stirred tank reactor continuously; The sample part of nylon salt solution is obtained in the downstream of introducing supplementary diamines; Sample part is carried out diluting and cooling, to form the nylon salt solution of the dilution of concentration and the 15-40 DEG C of temperature with 5-15%; Utilize the change of the pH value of the nylon salt solution of the online pH measured value monitoring dilution introducing the nylon salt solution supplementing diamines downstream; Adjust the 3rd feed rate to respond the change of pH value, with production pH value depart from target ph lower than ± 0.04 nylon salt solution.

As shown in Figure 9, in order to be conducive to carrying out on-line testing to the pH value of nylon salt solution in laboratory conditions, nylon salt solution is withdrawn from continuously from reactor, and will at least partially nylon salt solution, as being less than 1% importing recirculation circuit 141 and sample line 153.Sample line 153 comprises the device for pH value determination in laboratory conditions.Sample line 153 also can comprise cooler (not shown), to cool nylon salt solution.In other examples, this cooler can omit.The temperature of the nylon salt solution in sample line 153 and concentration are by adding water to regulate through pipeline 220.The sub-fraction of total water feed rate that this water is calculated by model.This water adds under the addition and temperature conditions of the temperature being enough to reach needed for the nylon salt solution example of the dilution measured for pH value and concentration.Also the further cooling of the sample to dilution can be comprised in described technique.The pH value of nylon salt solution measures in laboratory conditions at least partially, and then this nylon salt solution is as described herein is at least partially back to reactor 140.Then output signal 226 is supplied to controller 113 by online pH meter.

As described above, online pH meter 154 is for measuring the variability of the pH value of nylon salt solution.In preferred embodiments, the change of the pH value of nylon salt solution lower than ± 0.04, as lower than ± 0.03, or lower than ± 0.015.The pH value be similar under reaction condition is measured, and due to the skew of online pH meter measured value, online pH meter is in laboratory conditions used to change instead of the target ph of measuring pH.This is the feedforward control owing to can set target ph at least partly.If pH value changes, then by utilizing online pH meter to measure, the change of production technology can be detected.Being similar to secondary process to control, can regulating feed rate by sending a signal to flowmeter valve 216 and 218 to pipeline 215 and 217.These regulate the salinity that also can affect nylon salt solution.The change of this kind of salinity controls to be controlled by the water of flowmeter valve 214 by signal 213.

Because the described technique for the formation of nylon salt solution is continuous print, the pH value measurement result in online pH meter 154 can in real time (as continuously) or closely obtain in real time.In some embodiments, the measurement of pH can be every 60 minutes, as every 45 minutes, every 30 minutes, every 15 minutes or every 5 minutes carry out.The accuracy of the measuring method of pH value is ± 0.05, as ± 0.03 or ± 0.01.

Three grades of technology controlling and process

Although adopt feedforward control and feedback signal can contribute to reducing the variability of nylon salt solution parameter as shown in Fig. 6,7 and 9, the off-line type pH value analysis carried out under can adopting further analysis, especially laboratory condition is to monitor the homogeneity of nylon salt solution.These offline process in laboratory conditions control, and referred to as three grades of technology controlling and process, can comprise pH value and measure and/or the measurement of salinity.In one embodiment, the pH value of nylon salt solution can carry out off-line type mensuration in laboratory conditions, to determine whether to reach target ph.Off-line type pH value is measured also can detect any plant issue or adjustable deviation.In another embodiment, the pH value of the nylon salt solution recorded at laboratory condition off-line also can be used for adjusting the signal pipe line 215 and 217 being connected to flowmeter valve 216 and 218.The measurement of off-line type pH value in laboratory conditions can measure pH value ± 0.01.

Thus, in one embodiment, the utility model relates to one for controlling the technique of the continuous production of nylon salt solution, comprising: the model generating the target feed rate for setting dicarboxylic acid powder, to produce the nylon salt solution with target ph; Based on weight, measure the dicarboxylic acid powder from loss in weight feeder to feed pipe, thus control the variability of dicarboxylic acid powder feed rate, dicarboxylic acid powder is transferred in single continuous stirred tank reactor with target feed rate by described feed pipe; And respectively diamines and water are introduced single continuous stirred tank reactor with the first feed rate and the second feed rate, to produce the nylon salt solution with target ph; With the 3rd feed rate, supplementary diamines is incorporated in the recirculation circuit of single continuous stirred tank reactor continuously; Shift out sample from the nylon salt solution introducing the downstream supplementing diamines, measure for the off-line type pH value of carrying out nylon salt solution in the aqueous solution of 15-40 DEG C; Determine that online pH value measures the deviation measured with off-line type pH value; Utilize the on-line pH value measurement result devious of the nylon salt solution being positioned at supplementary diamines introducing downstream to monitor the change of the pH value of nylon salt solution; And adjustment the 3rd feed rate responds the change of pH value, with produce pH value depart from target ph lower than ± 0.04 nylon salt solution.

As shown in Figure 8, the nylon salt solution in sample line 153 be directed to by online pH meter 154 at least partially, obtain pH value measurement result wherein, and output signal 226 is directed to controller 113.Sample line 153 also can comprise cooler (not shown), to cool nylon salt solution before flowing through pH meter 154.Shifting out by pipeline 221 at least partially of nylon salt solution in sample line 153, and measure with laboratory pH meter 222.Water by pipeline 220 add in pipeline 221 with by Sample Dilution to specific concentration, then it is cooled to target temperature again, as between 15-40 DEG C or nearly 25 DEG C.In one embodiment, cooling water can be used for dilution and cooling sample.The pH value of the nylon salt solution in pipeline 221 is measured, and output signal 226 is sent to controller 113.Then the nylon salt solvent portions tested in laboratory conditions can combine with the sample after tested of return line 155, is then back to reactor 140 by pipeline 224.In some embodiments, the nylon salt solvent portions tested in laboratory conditions falls by the outside drain of pipeline 223 from technique 100.

For reaching laboratory condition temperature and concentration, the nylon salt solution example shifted out from recirculation circuit can use the water added through pipeline 220 to carry out diluting and cooling.Also temperature bath can be used to cool the nylon salt solution example of dilution.Sample can be withdrawn from as required, such as every 4-6 hour, every day or per week.When system perturbations, sample can frequently, is removed as per hour.Usually, off-line type pH analyzer can be used for the Deviation of equipments that in-line analyzer is described.Such as, if target ph is 7.500, online pH analyzer can record 7.400 and off-line analysis instrument can survey 7.500, and this just shows the Deviation of equipments of online pH analyzer.In one embodiment, whenever carrying out off-line measurement, exponentially weighted moveing average can be used for automatically departing from in-line analyzer.In certain embodiments, the output of off-line analysis instrument can be used for any deviation or the skew that correct in-line analyzer.In other embodiments, although in-line analyzer is not corrected, off-line analysis instrument can be utilized to monitor skew or deviation.In this respect, the change of in-line analyzer determination pH value is relied on, as being positioned at outside default acceptable variability.

In other embodiments, the target salinity of nylon salt solution measured by available off-line analysis instrument.The salinity measurement result of off-line also can detect any plant issue or adjustable deviation.When using multiple refractometer, each refractometer can be biased independently.

nylon polymerization

Nylon salt solution described herein can be directed in polymerization technique 200, to form polyamide, and especially nylon 6,6.Nylon salt solution directly can deliver to polymerization technique 200 by continuous stirred tank reactor 140, or is first stored in holding vessel 195, then delivers to polymerization technique 200, as shown in Figure 10.

Nylon salt solution of the present utility model has homogeneous pH value, and it can improve the performance of polymerizing polyamide technique.The nylon salt solution with homogeneous pH value is produce different polyamide products to provide reliable initiation material.This just substantially increases the reliability of polymerization product.Usually, polymerization technique to comprise from nylon salt solution evaporation water with concentrated nylon salt solution, and makes the nylon salt concentrated be undertaken being polymerized to form polyamide product by polycondensation.Described technique can use one or more evaporimeter 202.Evaporation of water or can add pressure and carries out in vacuum, to remove at least 75% of water in nylon salt solution, at least 95% of the water more preferably in nylon salt solution.Concentrated nylon salt 203 can comprise the water of 0-20wt.%.Polycondensation can be carried out in batch technology or continuous processing.According to required final polymeric articles, extra AA and/or HMD can be added in polymer reactor 204.In some embodiments, additive can be combined with polyamide product.

In order to realize the purpose of this utility model, suitable polyamide product can at least 85% carbochain between amide group be aliphatic.

When nylon salt solution is transferred to evaporimeter 202 by holding vessel 195, its temperature is maintained at more than its fusing point.This can be avoided blocking pipeline.In some embodiments, the steam obtained from evaporimeter 202 can be used for holding temperature.In other embodiments, the cooling water of heating can also be used.

Polymerization can be carried out in single-stage reactor or multi-stage polycondensation reactor 204.Extra monomer, AA or HMD, but preferably HMD adds by pipeline 205, to produce different nylon product 208.Reactor 204 can comprise the agitator for mixing nylon salt.Reactor 204 can have chuck, utilizes heat exchange medium to adjust temperature.Polycondensation reaction in reactor 204 can be carried out in an inert atmosphere, can add nitrogen in reactor 204.According to initial dicarboxylic acids and diamines, polymerization temperature can change, but usually above the melt temperature of nylon salt, more preferably higher than melt temperature at least 10 DEG C.Such as, the melt temperature comprising the nylon salt of hexamethylene diamine adipate is 165-190 DEG C.Therefore, polycondensation reaction can at 165-350 DEG C, as carried out under the temperature of reactor of 190-300 DEG C.Polycondensation reaction can be carried out under atmospheric pressure or pressured atmosphere.Nylon product 208 can the form of free-pouring solid product be taken out from reactor.

The water produced in polycondensation reaction can be removed by reactor draft tube liner 209 in the mode of vapor stream.Vapor stream can be condensed, and the gaseous monomer of escaping together with water, can be returned to reactor as diamines.

Also can carry out follow-up processing, as extruded, spinning, stretching or stretcher strain, to produce polyamide product.Polyamide product can be selected from by nylon 4, and 6, the group that forms of nylon 6,6, nylon 6,9, nylon 6,10, nylon 6,12, nylon 11 and nylon 12.In addition, polyamide product can be copolymer, as nylon 6/6, and 6.

Following non-limiting embodiment describes technique of the present utility model.

Embodiment

Embodiment 1

Adopt mechanical conveying system (i.e. screw rod/haulage chain) or pneumatic conveyer system (i.e. forced air, evacuated air or closed loop nitrogen), by container bag discharging, the discharging of liner container bag, the discharging of liner box container or hopper railcar discharge terminal, AA powder is moved to supply container from discharge system.

Required AA powder is moved into weight-loss type (L-I-W) dispenser by supply container, and it adopts PLC to regulate based on the low level of selected L-I-W hopper and a high position.Supply container measures AA powder by screw transporter or swinging feeder with enough loading speeds, described enough loading speeds make to equal at largest interval, and be preferably less than 1/2nd filling L-I-W dispenser hoppers of the minimum L-I-W discharge time from a high position to low level L-I-W storehouse, so that receive the feedback signal of L-I-W dispenser feed rate when the time of at least 67%.

The speed of L-I-W feed system adjustment L-I-W feed worm, detected by L-I-W feed hopper pressure measuring unit, to maintain the feed rate target received from scattered control system (DCS) by feed rate.

As shown in figure 11, by the feed rate variability of the adipic acid of loss in weight feeder, there is within the continuous feed cycle of 48h the feed rate variability lower than ± 5%.As shown in figure 12, within the cycle of 40h, the variability of feed rate can lower than ± 3%.As shown in figure 13, within the cycle of 18h, the variability of feed rate can lower than ± 1%.By eliminating the disturbance of the adipic acid feed rate caused owing to using volumetric feeder, use can improved feed rate variability performance for the loss in weight feeder of adipic acid.

Embodiment 2

For producing nylon salt solution Modling model according to continuous processing.Described nylon salt solution comprises water and hexamethylene diamine adipate.Described model is set, to reach the salinity of in nylon salt solution 63% and to obtain the target ph of 7.500.The feed rate of AA is determined in production based on required nylon salt solution.Based on the salinity that will reach and pH value, the feed rate of HMD and water can be determined.Adipic acid moves to loss in weight feeder with low variability as described in Example 1 from powder discharge system.

AA powder from loss in weight feeder directly supplies continuous stirred tank reactor by charging conduit, and described charging conduit is that nitrogen is with 20-30nm ³the speed of/h is sprayed to clean the steam skewed slot produced in feeding machine and reactor continuously.

Utilize the DCS model of the object library storage stored based on salt feed rate and the salt from salt reactor continuous stirred tank reactor, determine the DCS set-point of weight-loss type adipic acid charging rate.The feed rate of described salt is by coriolis mass flow meter measurement, and it non-immediate can use adipic acid feed rate to be intervally adjusted to desired value can set based on inventory model.Typically, adipic acid feed rate can directly with feed back to DCS loss in weight feeder feed rate together with use.

Concentration be 98% HMD solution store recirculating main from pressure controlled HMD and supply online static mixer.Utilize the coriolis mass flow meter measurement that input is provided to DCS, DCS utilizes the adjustment of feedforward ratio control circuit to enter the feed rate of the HMD incoming flow of static mixer, thus accurately controls the HMD that joins based on AA powder feed rate in continuous stirred tank reactor.This main HMD charging accounts for about 95% of HMD charging needed for technique.

By exporting for supplementary HMD valve the set point that the backfeed loop controlled adjusts DCS HMD ratio flow governor, being middle-grade to maintain the output of supplementary HMD valve, thus ensureing that described valve is positioned at controlled range continuously.

Deionized water supplies online static mixer from Stress control deionized water supply main.Utilize the coriolis mass flow meter measurement providing input to DCS, DCS utilizes the adjustment of feedforward ratio control circuit to feed the deionized water feed fluid flow rate of static mixer, accurately to control the water concentration of AA and HMD in continuous stirred tank reactor.The feed rate of deionized water sets in dcs, enters the vent condenser of reactor to make deionized water with required charge velocity.

Online static mixer product stream directly enters the top of the CSTR being positioned at adipic acid feed well 0.3-1.0 rice, and this specific position is conducive to the dissolving of the adipic acid charging helping to enter.

Utilize the pH meter pH value determination continuously of the redundancy being arranged in the sample recirculation circuit that after the filtration provided by the recirculation pump of reactor, temperature and flowing control.The pH value input of a pair on-line pH value measurement result constantly compared utilizing DCS to select, DCS adjustment supplements the feed rate of HMD to maintain pH value target set point in dcs.Supplement HMD charging and be about 5% of total HMD charging in technique.

Utilize and to carry out in the discrete interval of reactor downstream, and condition be 9.5% concentration and 25 DEG C thus reach the sample pH analysis of the most sensitive of the acid of the function as pH value/amine balance, or by from the continuous input of constantly diluting/adjusting the product of reactor or the pH value from the in-line analyzer of concentration to 9.5% of the product of subsequent storage container (if preferably talk about) and 25 DEG C, the set-point of Corpus--based Method algorithm adjusted to ph controller.

Supplementary HMD is injected in the pump suction of the recirculation circuit of main reactor, to reach the fastest response time to pH meter, and ensures, within the shortest time, reactor product is adjusted to target.Pump is used for HMD and the mixing of reactor product salt, so that ensure that pH meter and densimeter are homogeneous phase solution when measuring respectively.

CSTR comprises reactor chamber and recirculation circuit.Recirculation circuit to comprise a part of nylon salt solution circulation to the first loop of reactor with by a part of nylon salt solution guiding value pH meter, is then back to the sample line of reactor.Sample line can comprise cooler, so that nylon salt solution is cooled about 5-10 DEG C from temperature during its outflow reactor.Measure the pH value of the nylon salt solution of cooling continuously.Cooled nylon salt solution is back to reactor.By the measurement feedback of pH value to technology controlling and process calculator, and adjustment model.The feed rate of described model to HMD adjusts.

By a part of nylon salt solution off-line, then by this portions of nylon salting liquid pH value determination in laboratory conditions.In order to the nylon salt solution measured in laboratory conditions, nylon salt solution with water is diluted to concentration and is about 9.5%.By temperature bath, the nylon salt solution of dilution is cooled to about 25 DEG C.Measure the pH value of nylon salt solution in laboratory conditions, and compare with target ph and on-line pH value measurement result.Then adjustment model is to provide the feed rate of the HMD of the low variability that can ensure compared with target ph.

Utilize the same spline filter provided by the recirculation pump of reactor, the refractometer of redundancy in temperature and the controlled sample recirculation circuit of flowing measures concentration in reactor continuously.The concentration input of a pair that constantly compares that utilizes DCS to select online concentration measurement, DCS adjusts the set-point of DCS deionized water ratio flow controller to maintain concentration target set point in dcs by backfeed loop.

By the water lev el control in reactor, reactor product is sent to salt storage place continuously.This transmission comprises at least one group of filter cartridge type filter be arranged in parallel, and it is 34.5kPa (5 pounds/square inch) initial cleanness Pressure Drop to the maximum for having when flowing to the maximum instantaneous salting liquid transfer rate of storage place and designs.When using synthetic fibers degree of depth filter core or folded membrane filter core, filter core gets rid of efficiency, and to have minimum be the absolute nominal value of 10 μm, maybe when use be wound around cotton fiber filter core time, having minimum is the rated value of 1 μm.The selection of filter based on have for minimum be the filter core of the rated value of the operating temperature of 110 DEG C.

Nylon salt solution, constantly recirculated through salt storage tank, preferably uses the tank injector mixer be arranged at from 0.5-1 rice at the bottom of tank, for tank concentration change the soonest mixing efficiency is maximized.

For the salinity of 63%, the temperature of salt storage tank flows through the vapor flow speed of recirculation line heat exchanger by adjustment and controls at 100-105 DEG C.Nylon salt solution in storage tank has the homogeneous pH value of 7.500 ± 0.0135.

Embodiment 3

As prepared nylon salt solution in embodiment 2, difference is to carry out online pH mensuration in laboratory conditions: at about 25 DEG C, concentration about 9.5%.

Comparative example A

Imitate as the model in embodiment 2 and technique, difference is to use volumetric feeder but not loss in weight feeder.Because the change of AA powder feed is very large, model is unpractical.The pH value of nylon salt solution departs from target ph and is greater than 0.120 and changes.Thus, the vicissitudinous crystallization temperature of nylon salt solution tool and boiling temperature.Therefore, the poor controllability of pH value causes obviously higher freezing point, thus needs higher processing temperature with the danger of pre-crystallization-preventive.Due to the boiling point of change, the controlling of this difference also causes nylon salt solution to seethe with excitement, and therefore reduces the output of nylon salt solution.

Comparative example B

Imitate as the model in embodiment 2 and technique, be use second CSTR without part.Nylon salt solution takes out from first CSTR, and feeds second CSTR.The pH value of nylon salt solution is measured between first CSTR and second CSTR.According to pH value and target ph, extra HMA and/or water are joined in second CSTR.From second CSTR, migrate out nylon salt solution, and measure its pH value.PH value departs from target ph 0.120 pH value unit and changes.Need extra CSTR to regulate the pH value of this nylon salt solution further, thus cause the increase of cost of investment and operating cost.

Although be described in detail the utility model, the revision in scope and spirit of the present utility model it will be apparent to those skilled in the art that.All publications discussed above and document are incorporated into herein by way of reference.In addition, should be understood that, described aspect of the present utility model and multiple embodiment and multiple feature can integrally or partly carry out combining or exchanging.In aforesaid multiple embodiment, those of skill in the art would recognize that these embodiments mentioning other embodiments suitably can be combined with other embodiments.Further, those skilled in the art recognize aforesaid explanation by embodiment only for explaining the utility model, do not form any restriction of the present utility model.

Claims

1., for the production of the reactor of nylon salt solution, comprising:

For the production of the continuous stirred tank reactor of nylon salt solution, comprising:

For dicarboxylic acid powder being introduced the first entrance of described continuous stirred tank reactor;

For the first diamines charging being introduced the second entrance of described continuous stirred tank reactor, contiguous first entrance of wherein said second entrance;

Be attached to one or more baffle plates of the inwall of described continuous stirred tank reactor;

Extend through the shaft at the center of described continuous stirred tank reactor, wherein said shaft comprises at least one top impeller and at least one lower impeller; And

Comprise the recirculation circuit of the binding site for introducing the second diamines charging in the upstream of pump and sample loop; And for nylon salt solution to be directly transferred to the pipeline of holding vessel from the recirculation circuit of continuous stirred tank reactor, wherein said pipeline is not containing any entrance for introducing other monomers, to prevent from other monomers being transferred to described pipeline or entering holding vessel, wherein, reactor comprises single reactor.

2. reactor according to claim 1, wherein, at least one lower impeller described and at least one top impeller described comprise blade turbine respectively.

3. reactor according to claim 1, wherein, described at least one upper leaf wheel has the inclined-plane be mutually biased with the inclined-plane of at least one top impeller described.

4. reactor according to claim 1, wherein, described sample loop comprises at least one in-line analyzer of pH value for measuring nylon salt solution and/or salinity.

5. reactor according to claim 1, wherein, described first entrance and the second entrance are arranged in above the liquid level of continuous stirred tank reactor.

6. reactor according to claim 1, wherein, described continuous stirred tank reactor comprises the 3rd entrance for introducing water charging.

7. reactor according to claim 1, wherein, described continuous stirred tank reactor comprises internal heating coils further.

8. reactor according to claim 1, wherein, recirculation circuit comprises heat exchanger, to adjust the temperature in continuous stirred tank reactor.

9. reactor according to claim 1, wherein, described continuous stirred tank reactor comprises one or more temperature controller and one or more pressure controller, to keep temperature and the normal pressure of 60-110 DEG C.

10. reactor according to claim 1, described reactor comprises the gas port for introducing nitrogen further.

11. reactors according to claim 1, described reactor comprises the vent condenser for being back to by condensable diamines in continuous stirred tank reactor further.

12. reactors according to claim 1, wherein, described continuous stirred tank reactor and described pipeline are constructed by corrosion resistant material and form.

13. reactors according to claim 1, wherein, described continuous stirred tank reactor keeps at least 50% full liquid level.

14. reactors according to claim 1, comprise the loss in weight feeder for entering the dicarboxylic acid powder in feed pipe based on weight metering further, dicarboxylic acid powder enters in the first entrance of continuous stirred tank reactor with the transfer of the feed rate of low variability by described feed pipe.

15. reactors according to claim 1, wherein, described pipeline comprises the one or more filters for filtering nylon salt solution before holding vessel.