Background technology
Fanglun l414 is claimed aramid fiber II or p-aramid fiber (Para-aramid Fibar) again, and the formal name used at school PPTA adopts low temperature solution polymerization technology to make by paraphthaloyl chloride (TPC) and two kinds of monomers of p-phenylenediamine (PPD) (PPDA).This polymerization process is following: PPDA forms premix with solvent in advance; After premix is cooled to 5~10 ℃ with partial melting TPC (about 85~90 ℃) hybrid reaction; Form prepolymer solution; This prepolymer solution is cooled to 10~15 ℃, in blender, mixes the continuous polycondensation reactor that gets in back with remaining fusion TPC and reacts.
During mixing, get into prepolymer liquid inventory in the blender and be about ten times of TPC flow of fusion, both temperature differ 70~75 ℃, and the freezing point of TPC is about 81~84 ℃, and mixing temperature generally is controlled at 30~35 ℃.Two kinds of monomer stoicheiometries meterings that described polycondensation reaction requirement mixes accurately, process is continuous and moment mixes.Mainly there is following problem when adopting the blender of mentioning among traditional static mixer, concentric jet mixer, T type blender and the patent CN 101195681A to mix:
(1) traditional static mixer utilizes its particular structural to make mixing of materials, and its mixability depends on design of special runner and mixed flow process, but can not guarantee that two kinds of monomer moments mix.Simultaneously two strands of materials fully contact, and the prepolymer solution of big flow low temperature has reduced the temperature of hybrid chamber, make that unmixing TPC produces in TPC inlet and the device to solidify, and cause stopping up in TPC inlet and the device, can't guarantee that mixed process carries out continuously.
(2) jet mixer is a flow at high speed of injecting second kind of mixing of materials chamber through first kind of material with one heart; Make material realize mixing; But because the flow velocity of second kind of material is low in the mixing chamber, distance is short, and the part that two kinds of storerooms can reach turbulence state simultaneously is few; There are a large amount of laminar regions, are difficult to realize instantaneous mixing fully.
(3) T type jet mixer is realized mixing of materials through the head-on collision mode; Can satisfy instantaneous mixed uniformly requirement; If but the ratio of two strands of mass flows differs greatly (for example the polymerization process of Fanglun l414 is 10~18: about 1) when mixing, less TPC melt one side of bump back logistics deflection flow is prone to flow to the wall of blender; Simultaneously because rum point deflection TPC jet; Big flow low temperature logistics has reduced near the temperature the TPC outlet, causes TPC to solidify at outlet jet pipe place, causes mixed process not carry out continuously.Though can carry out the mediation of TPC pipe through needle valve is set, be difficult to evenly owing to mix to interrupt making mixing, the mixing arrangement structural reliability is poor.Because the TPC melt flow is little, under high flow condition, be easy to penetrate the material of big flow in addition, also cause mixing inhomogeneous.
(4) blender mentioned of patent CN 101195681A is provided with high-speed stirring apparatus in hybrid chamber, offers the discharging screw thread on the shaft to shorten the time of staying of material, reaches the purpose that realizes instantaneous mixing.Because agitating device makes material be full of whole hybrid chamber, has reduced the temperature of hybrid chamber, causes TPC to solidify in the porch easily, mixed process is interrupted.
As everyone knows, for the strict polymerisation of stoicheiometry, mixed process is most important, and blender need satisfy continuously, requirement uniformly.The inventor has carried out big quantity research and has thought, the material mixer of Fanglun l414 polymerization process need satisfy following requirement:
(1) two strand of material needs to mix in moment.Only mixing polymerisation just possibly be accomplished at short notice; The uniformity coefficient of prepolymer initial mixing greatly influences the local monomer stoicheiometry of reaction system; And determining the molecular weight distribution of final polymer, the initial mixing effect directly influences the time of staying of material in follow-up polycondensation reactor simultaneously;
(2) mixed process need be carried out continuously.Flow differs greatly during two bursts of mixing of materials; Receive the influence of the big flow material of low temperature, the temperature of hybrid chamber is lower than the fusing point of TPC, and the mixing that blender should be avoided causing owing to the TPC frozen plug mouth of pipe is interrupted; Cause the instability of monomer stoicheiometry, the product quality that can't obtain to expect;
(3) the blender volume should be as far as possible little.In the Fanglun l414 polymerization process; Existence again to the phase transition process of solid phase, for guaranteeing that material gets into polycondensation reactor smoothly, should make material still be in liquid phase state at mixer outlet from the liquid phase to the gel phase; Therefore the blender volume need be as far as possible little, to shorten the material time of staying therein;
(4) avoid backflowing during mixing of materials.The existence of backflowing influences the stoicheiometry of two kinds of monomers, causes the monomer polymerization degree uneven easily, thereby causes the end product molecular weight distribution wide.
For satisfying above-mentioned requirements, the mixing arrangement that needs exploitation to make new advances.
The specific embodiment
Referring to Fig. 1-6; The invention provides a kind of multistage, multi-direction Y-type impinging jet mixer; It is provided with multistage fluidic channel, is an acute angle (wherein 15 is two one-level jets, and 18 is two secondary jets) between the jet 15 or 18 of each fluidic channel at the same level; And (wherein 16 are the impingement region of one-level jet to be intersected in the same impingement region 16 or 19 of this grade jet; 19 is the impingement region of secondary jets), mixed flow 17 that forms behind the impinging jets at different levels or 20 path be located along the same line (wherein 17 are the mixed flow of one-level jet, and 20 for comprising the secondary jets mixed flow of one-level jet mixed flow); Not the impingement region of jet at the same level alternate on this straight line, join or overlapping distribution; The distribution mode of the impingement region of jets at different levels can be identical, also can be different, promptly can all be distribute alternately, or all be join distributions, perhaps all be overlapping distribution; Also can be that the part streams impingement region distributes alternately, the part streams impingement region joins distribution, the overlapping distribution of part streams impingement region, described overlapping comprise overlapping fully, overlap and one comprise another.
Usually, said fluidic channel can be 2 grades or 3 grades (for example the progression of the fluidic channel of each embodiment shown in the drawings is 2 grades), so as satisfy mix require in, simplified apparatus structure as far as possible.
With the fluidic channel quantity of one-level generally can be 2 or 3 (for example the quantity of the fluidic channel at the same level among each embodiment shown in the drawings is 2).
Each fluidic channel with one-level generally should distribute symmetrically.
For guaranteeing the proper flow of mixed flow, the direction of common mixed flows at different levels should be vertically downward.
The direction of mixed flow is controlled by the multiple parameters such as direction, flow and flow velocity of each jet at the same level and prime mixed flow; Can through hydromechanical calculating and/or through the experiment or computer simulation experiment under certain condition; Through the design of rational flow angle, jet pressure and effluxvelocity, the mixed flow direction behind the assurance impinging jet is still for vertically downward.For the certain blender of structure, abundant mixing that can guarantee bump and the mixed flow direction behind the bump through the pressure or the flow velocity of adjustment each jet at the same level.
In the mixed flow direction for vertically downward the time, the center that is centered close to previous stage impinging jet zone in the impinging jet of back one-level zone following or overlapping with the center in previous stage impinging jet zone.For the mixed flow direction is the situation of other directions, the front at the center that is centered close to previous stage impinging jet zone in the impinging jet zone of back one-level or overlapping with the center in previous stage impinging jet zone.The impingement region of adjacent two stage jet generally can be overlapping (can be accomplish overlapping; Or overlap; Or one comprise another), side edge or adjacent; Make two stage jet clash into simultaneously and mix the bump mixing of carrying out back one-level jet after perhaps the previous stage impinging jet mixes at once, help shortening total bump incorporation time like this.
The centerline average of each jet at the same level should intersect at a point, and this point can be called rum point, to guarantee the validity of bump.
This blender can comprise a housing 5, is provided with mixing chamber in the housing, and said jets at different levels are in mixing chamber inner impact and mixing, and the final mixed flow that forms flows to the mixing chamber bottom, and discharges through corresponding pipeline.The common pref. cylindrical housing of said housing; In housing, form a cylindrical space, it is that square waits other shapes that said housing also can adopt the cross section, should have certain symmetry usually; For example axial symmetry or multidirectional facing are claimed, have center line (or claiming line of symmetry).
Said fluidic channel can adopt tube shaped; Promptly the pore by pipe fitting constitutes; Also can be employed in the form that through hole is set on the physical member; Promptly constitute, in view of comprising that through the pipe fitting setting fluid passage of fluidic channel can adopt prior art easily, so the fluidic channel among the embodiment of demonstration constitutes by the through hole on the physical member in each figure by the through hole on the physical member.According to prior art, also can constitute such fluidic channel structure through pipe fitting, realize identical technique effect.
For example; The top of said housing can be provided with a body 12; Said body is provided with some jet via-holes that distribute alternately 1,2,3,4, and (wherein 1 and 2 are the jet via-hole of one-level fluidic channel; 3 and 4 is the jet via-hole of secondary jets passage), be provided with a jet orifice plate 13 that is connected as a single entity with said body below the body, can said body and said jet orifice plate be tightened together through plurality of fixed bolt 14.Said jet orifice plate is provided with some oblique jet orifices 24,25, and (wherein 24 is the jet orifice of two one-level fluidic channel; 25 is the jet orifice of two secondary jets passages); Each oblique jet orifice on the said jet orifice plate is corresponding one by one with each jet via-hole on the said body; Described each fluidic channel is formed by connecting these said one to one jet orifices and said jet via-hole; The import of wherein said jet via-hole constitutes the import of fluidic channel, the outlet of the export mixes fluidic channel of said jet orifice.
The straight hole that said jet via-hole extends below on can being; Said jet via-hole is the inclined hole towards the housing center line; Because jet direction is mainly limited jet orifice; So the jet that comes out from each jet orifice will flow along the bearing of trend of jet orifice, and is intersected on the center line of housing, the bump back forms mixed flow and flows downward along the housing center line.
Body and jet orifice plate are divided into two parts, help the processing and manufacturing of fluidic channel and whole blender, and can adopt material different according to different wear-resisting requirements.
The top of said housing can be provided with mounting flange 11, so that connect with other devices.
When adopting pipe fitting to form above-mentioned fluidic channel, can use some pipe fittings to substitute above-mentioned body and jet orifice plate.The some pipe fittings that constitute fluidic channel can be installed on the dividing plate of case top; The pipe fitting upper end is the fluidic channel import that is used to connect corresponding pipeline; The lower end is passed said dividing plate and is extended in the housing, forms the outlet of fluidic channel, can be provided with rectangular nozzle in this outlet.
Can also adopt other modes that adapt to arbitrarily to constitute the fluidic channel of same structure.
When the quantity of fluidic channel at the same level is 2, generally should be positioned on the plane passing the housing center line, and when having only the two stage jet passage, 2 fluidic channel of back one-level generally should be positioned on the perpendicular plane, plane, previous stage fluidic channel place.
The preferred rectangle of the cross sectional shape of said jet orifice, this rectangular opening length (L) and width (H) can confirm that this rectangular jet hole can form rectangle or be similar to the jet of rectangle, plays good impact effects according to the bump needs.
Two jet orifices of first order fluidic channel are isometric (L) jet orifice, guarantee that the striking face contact is complete, no leakage current, non-draining phenomenon.The principle that momentum equated when two jet orifice width (H) need be according to impinging jet calculates.The scope of two hole angle approximately is controlled between 60~120 °; The different values of α directly influence mixed effect, will obtain the optimal value of α during design according to material density, flow, viscosity, temperature and other factors through calculating and/or experiment or simulated experiment mode.
The projection of incident direction on horizontal plane of the incident direction of two jet orifices of second level fluidic channel and first order jet orifice generally should be 90 ° of layouts; Form the form of the multidirectional impinging jet of two inter-stages thus; Second level impinging jet point absolute altitude can be designed to identical with the first order or a little less than the first order, this absolute altitude is confirmed by the interval between angle between the secondary jets hole and two jet orifices usually.Partial two jet orifices also will be taked wide design, and the jet width should be able to contain the diffusion breadth of the mixed flow vertically downward of first order collision back formation down.Angle between the jet at the same level in the two-stage can be identical, also can be different, should be as the case may be following mixed effect definite.
Space in the housing is a mixing chamber; The bump of jet is blended in mixing chamber to carry out, and need carry out the reaction of protections such as nitrogen for some, protective gas turnover pipe can be set respectively in the upper and lower of housing or import and export 7,8; So that feed protective gas such as nitrogen, the protection of realization nitrogen etc.
Can be provided with annular scraper 6 with the inner walls matched in clearance in the said mixing chamber (according to the cross sectional shape of housing; Can be annular, side's annular or the like the various and corresponding annular of housing cross sectional shape), said annular scraper is installed in to be scraped on the knife support, and the said knife support of scraping is provided with some guide posts 22; Said body is provided with vertical scraper pilot hole 23; Said guide post extends in the said scraper pilot hole, with said scraper pilot hole matched in clearance, and is connected with the drive unit that the drive guide post moves up and down; For example the rammer drive unit can regularly be removed the colloid substance that bonds on the mixing chamber inner walls thus.
The material that is incubated or heats up for needs; Can corresponding fluidic channel be arranged to be incubated fluidic channel; Be provided with moist closet 21 around the said insulation fluidic channel; Said moist closet can be looped around around the corresponding fluidic channel usually, and is connected with heating agent connection turnover pipe or imports and exports 9,10, realizes insulation or intensification to corresponding fluidic channel through inserting heating agent.
When being applied to the polymerization process of Fanglun l414, two kinds of materials that get into blender are respectively PPDA solution and TPC melt, and wherein the temperature of PPDA solution is lower; Be lower than the freezing point of TPC, and the temperature of TPC melt is higher than freezing point, because the former flow is much larger than the latter's flow; If with two fluidic channel that are mutually Y shape or T shape the required material total number of above-mentioned reaction is spurted into blender, because momentum is different, the percussion flow meeting of formation forms bias current; Flow to wall; Cause local T PC melt temperature to reduce, form bonding group, be difficult to realize the requirement of successive reaction.Therefore; After adopting the present invention; Can two fluidic channel that are mutually 60~120 ° Y shape distribution be formed the one-level fluidic channel; Other two fluidic channel that are mutually 60~120 ° Y shape distribution are formed the secondary jets passage, and fluidic channel at different levels are confirmed the distance between two fluidic channel according to the difference of mass flow, density, temperature, viscosity, to guarantee two bursts of momentum of impinging jet approximately equals; Two fluidic channel all need guarantee to have isometric rectangle outlet in each grade fluidic channel, and the width of two rectangles outlet should calculate according to material properties to be confirmed, should make two bursts of impinging jet face contacts that collide complete, no leakage current, non-draining phenomenon; Particularly should keep rational distance between its outlet between each level two fluidic channel, not have each other heat transmission, the TPC melt does not have and solidifies, stops.
According to above-mentioned requirements; In two fluidic channel of the first order, a fluidic channel imports the TPC melt, and another fluidic channel imports the PPDA solution identical or close with TPC melt momentum; Remaining PPDA solution can be equally divided into 2 bursts of percussion flows; Import second level fluidic channel, guaranteed that thus percussion flow momentum at different levels are identical, and can form vertical film inflow polycondensation reactor.At this moment, the two stage jet passage can be arranged as and be mutually 90 ° on floor plan, and percussion flow is multidirectional bump attitude.The absolute altitude of impinging jet point at the same level can be not identical, also can be different, but need to guarantee that polycondensation reaction thing molecular weight distribution is in reasonable range.Adopt same thinking, also can the present invention be used for other any mixing temperatures has two or more materials than big difference, and can satisfy with the stoichiometric coefficient is the continuous mixing between the component of proportioning, can satisfy the even mixing of liquid and melt; Can be used for mixed traffic has two or more materials than big difference, can make the momentum of two bursts of percussion flows in the peer accomplish equal basically.
In this specification, the progression of jets at different levels is pressed the natural number serial number, numeral is little be before, and in statement during, be the place ahead with the flow direction of jet and mixed flow with respect to the direction of jet or mixed flow, after promptly the position of first process is, after through the position be before.