EP2697428A1

EP2697428A1 - Method and nozzle arrangement for introducing chemicals and/or additives into a process flow of a production process

Info

Publication number: EP2697428A1
Application number: EP12715884.8A
Authority: EP
Inventors: Thomas Jaschinski
Original assignee: Voith Patent GmbH
Current assignee: Voith Patent GmbH
Priority date: 2011-04-13
Filing date: 2012-04-03
Publication date: 2014-02-19
Anticipated expiration: 2032-04-03
Also published as: CN103608517B; CN103608517A; DE102011007274A1; WO2012139921A1; EP2697428B1

Abstract

Specified is a method for introducing chemicals and/or additives into a process flow of a production process, in particular of a process for producing a fibrous or nonwoven web, by means of a nozzle arrangement, in which method use is made of a nozzle arrangement having at least one mixing zone and having a throttle device arranged in the region of the nozzle outlet opening, the flow characteristic of which nozzle arrangement is variable and/or which nozzle arrangement can, for variability of the flow characteristic in the region of the nozzle outlet opening, be exchanged for a respective different throttle device with a different flow characteristic, in each case two media are mixed with one another in a respective mixing zone, and to set different flow speeds of the mixture flow which emerges from the nozzle outlet opening and which is to be introduced into the process flow, the flow characteristic of the throttle device is in each case correspondingly varied or a respective throttle device is exchanged for a throttle device with a different flow characteristic. Also specified is a nozzle arrangement for carrying out a method of said type.

Description

Method and nozzle arrangement for introducing chemicals and / or additives into a process stream of a production process

The invention relates to a method for introducing chemicals and / or additives into a process stream of a production process, in particular a process for producing a fiber or nonwoven web, by means of a

Nozzle assembly. It further relates to a nozzle arrangement in particular for

Implementation of the procedure. The increased costs especially for energy, raw materials, fresh water and chemicals require their efficient use. In particular, in the production of a fiber or nonwoven web, the consumption of process and

Functional chemicals, but also the use of fresh water as

Dilution medium in the chemical treatment by providing an efficient method for metering and mixing chemicals into the process stream can be significantly reduced.

The principles hitherto used in the metering of fluid chemicals in a process stream for the production of a paper or nonwoven web, inter alia, have the disadvantage that the chemical concentration in the nozzle can not be adjusted and the nozzle instead one to a certain

Concentration adjusted chemical must be supplied.

A respective change in the concentration of chemicals in the relevant

Feeder is so far only about a change in the flow rate of the

Dilution medium possible. In addition, the dosing concentration can hitherto only be adjusted by changing the initial concentration of the fluid chemical used. Also in the latter case leads a reduction of

However, chemical concentration at the same chemical dosage amount leads to an increase in volume and, with unchanged nozzle geometry, to a change the flow velocity at the outlet of the nozzle. However, a change in the concentration of chemicals now has a direct influence on the effect of the chemical in question. With a change in question, the chemical can no longer be dosed with the optimum metering concentration into the process stream.

A disadvantage of the metering devices used hitherto is that their geometry and in particular the geometry of their outlet opening does not change and the respective desired flow rate can not be achieved without changing the chemical concentration.

The invention has for its object to provide an improved method and an improved nozzle assembly of the type mentioned, in which the aforementioned disadvantages are at least substantially eliminated. In general, the efficiency of the metering and mixing of chemicals or additives in the process stream should be increased.

Regarding the method, the object is according to a first aspect of

Invention solved by a nozzle arrangement with at least one

Mixing zone and arranged in the region of the nozzle outlet opening

Throttle device is used whose flow characteristics can be variably changed and / or which is exchangeable for a variable changeability of the flow characteristic in the region of the nozzle outlet opening against a respective other throttle device with a different flow characteristic,

in each case at least two media are mixed together in a respective mixing zone and

for setting different flow velocities of the

Nozzle outlet opening exiting, to be introduced into the process stream

Mixed flow respectively the flow characteristics of the throttle device

amended accordingly or a respective throttle device by a

Throttle device is exchanged with a different flow characteristics. By the flow velocity in the region of the nozzle outlet over the

Flow characteristic of a throttle device is variably changeable, this flow rate can also be independent of the particular

Chemical concentration and be set at a constant dosage of the chemical. The same applies to any added additives. By setting the optimum flow rate, for example a retention agent diluted in the nozzle arrangement, the flocculation characteristic, for example, can be favorably influenced. Preferably, a nozzle arrangement with a plurality of mixing zones arranged one behind the other in the main flow direction is used.

In particular, at least one injection stream can be supplied to the nozzle arrangement via a respective nozzle inlet opening.

According to a preferred practical embodiment of the method according to the invention, at least one in particular fluid chemical and / or at least one additive stream is fed to at least one mixing zone. It is also conceivable, in particular, for at least one dilution fluid stream to be fed to at least one mixing zone.

According to a particularly advantageous embodiment, at least one

Mixed zone fed at least one gas stream.

It is particularly advantageous if in a respective mixing zone the

Mixing of the media in question promoting turbulence can be generated. Preferably, the turbulences in a respective mixing zone are at least partially formed by a cross-sectional widening of the main flow cross section of the

Nozzle arrangement generated. Of particular advantage here is if at least one Chemical stream, at least one additive stream, at least one gas stream and / or at least one dilution fluid stream is introduced into the region of maximum turbulence of the mixing zone, whereby an optimal mixing is ensured.

According to a further aspect of the invention, the method for introducing chemicals and / or additives into a process stream of a

Manufacturing process, in particular a process for producing a fiber or nonwoven web, by means of a nozzle arrangement, characterized in that at least one zone, in particular mixing zone, the nozzle assembly at least one

Chemical stream, in particular gas stream supplied and in this reaction or mixing and reaction zone with the chemical in question and at least one other reactants, a chemical reaction, in particular precipitation reaction is brought about.

In this case, the precipitation product in the respective zone can advantageously be admixed with an injection stream fed to the nozzle arrangement via a nozzle inlet opening. In certain cases, however, it is also advantageous if the chemical reaction, in particular precipitation reaction, in the respective zone is brought about with at least one further reaction partner which is contained in an injection stream supplied to the nozzle arrangement via a nozzle inlet opening, in particular partial fluid stream.

Advantageously, also in the present method according to the

Use of at least one reaction or mixing and reaction zone

concerned second aspect of the invention again an inventive

Throttle device used, but this is not mandatory. A nozzle arrangement according to the invention which is suitable in particular for carrying out the method for introducing chemicals and / or additives into a process stream of a production process, in particular a process for producing a fiber or nonwoven web, is characterized in that the nozzle arrangement has a base section with at least one mixing and / or or

Reaction zone has, which are fed to at least two media to be mixed together or chemically reacting with each other, and preferably comprises a arranged in the region of the nozzle outlet opening throttle device whose

Flow characteristic variably changeable and / or which is connected to enable a respective exchange against another throttle device with a different flow characteristics releasably connected to the base portion.

The nozzle arrangement preferably comprises a plurality of mixing and / or reaction zones arranged one after the other in the main flow direction.

According to a preferred practical embodiment of the nozzle arrangement according to the invention, the main flow cross-section thereof in the region of at least one mixing and / or reaction zone has turbulence-generating

Cross-sectional expansion on.

Conveniently, the nozzle outlet opening via the throttle device is also completely closable. The nozzle arrangement can thus be used, for example

Cleaning purposes are completely shut off against the process stream. It is particularly advantageous if the throttle device is a particular as

Quetschventil executed valve with preferably at least one in particular mechanically, pneumatically or hydraulically acted upon flexible hose or flexible sleeve comprises. With the method according to the invention and the invention Nozzle arrangement significantly increases the efficiency of metering and mixing of chemicals and / or additives into the process stream. The invention is of particular advantage in particular in the production of a fiber or

Nonwoven web can be used.

According to the invention, in one zone of the nozzle arrangement, an admixture of one medium with another can take place, in one or more further downstream zones such a mixing process can repeat before the resulting mixed stream preferably by an adjustable, advantageously also fully closable throttle device in the

Process flow is metered. The optional throttle device may include the function of a valve, whereby the outlet opening of the nozzle arrangement and thus the flow velocity in the region of the outlet opening can be variably adjusted or controlled and / or regulated. According to a simpler one

Embodiment is also a replaceable throttle device conceivable. In this case, for example, a corresponding construction of the housing of the nozzle assembly is provided by which a respective throttle device can be easily exchanged for another throttle device with a different flow characteristics.

The nozzle arrangement can be designed, for example, as a mixing nozzle with one or more mixing zones arranged at least substantially successively in the main flow direction. In this case, at least one fluid chemical or fluid additive, for example an injection stream, can be added in a mixing zone. For example, one or more mixing zones may also be admixed with two or more fluid chemicals or additives at the same time and, for example, mixed with the injection stream, which may, for example, also be a partial stream. This mixing principle can be repeated in one or more subsequent mixing zones. The preferably fluid chemical or additive to be metered may be, for example, a retention agent, for example polyacrylamide (PAM), polyethyleneimine (PEI), polyamidoamine (PAAm), crosslinkable polyamidoamine resins, polyDADMAC, polyvinylamine (PVAm) , Polyethylene oxide (PEO).

Moreover, the chemical to be metered may also be microparticles or nanoparticles, for example bentonite or a silicate.

Further, the chemical to be dosed may contain starch, a biocide and / or, for example, a dye or an optical brightener.

In addition, the chemical may be, for example, neutral size agents such as alkyl ketene dimer (AKD) or alkenyl succinic anhydride (ASA). In addition, for example, mineral substances, such as calcium carbonate and / or titanium dioxide, in the form of a "slurry", are dosed.

The mixing nozzle may in particular comprise a cylindrical housing in which one or more mixing zones forming mixing zones are located. A respective mixing element may, for example, comprise a cylindrical body, the outer peripheral surface of which has an annular recess in which holes are bored in the radial direction, which open into the central, axial bore of the mixing element. The annular gap of a respective mixing element may be connected through the wall of the housing with one or more media feeds. The individual mixing elements can via seals against each other and the

Be sealed housing wall. The angle between the axial bore and the radial bores is expediently in each case 90 °.

The cylindrical diameter of the inner cross-sectional area (axial bore) of a respective preceding mixing element in the main flow direction is preferably smaller than the cylindrical diameter of the inner cylindrical, in particular circular-cylindrical cross-section of the respective subsequent

Mixing element. Such a cross-sectional enlargement or increment may also be provided in the region of the front end of the first mixing element viewed in the main flow direction. The step-like enlargement of the

rotationally symmetrical cross section of u.a. from the succession of the individual mixing elements resulting cylindrical flow channel leads to the following effect.

The increase in the flow cross section of the cylindrical bore causes a return vortex in the flow. It comes especially in the

Boundary layers of the vortex to large shear stresses that cause turbulence, by means of which an efficient mixing of the introduced fluid chemical or additive or gas is achieved in the mixing element. The forming by the cross-sectional widening shear field can therefore for the

Interference of the respective fluid media are used. In this case, the chemical or the additive or gas can be introduced in particular into the zone of maximum turbulence of the respective mixing element or zone. This can be done for example by a corresponding arrangement of provided for the application of the medium in question radial holes.

In particular, those embodiments of the nozzle arrangement are conceivable in which the injection flow is initially in the inner cylindrical cross section of the in

Main flow direction considered first mixing element out and then over a step jump in which a correspondingly larger inner cylindrical cross-section having subsequent mixing element is continued. The ratio between the diameter D ₂ after the increment and the

Diameter Di before the increment (increment ratio = D ₂ / Di) is advantageously in a range between about 1.1 to about 5.0, more preferably in a range of about 1.1 to about 2.0 and preferably in a range of about 1, 2 to about 1, 5. The length Li of the first cylindrical viewed in the main flow direction

Mixing element is advantageously dependent on the step-like extension and is expediently 10 to 50 times the length (D ₂ - Di) / 2. The turbulence is greatest in this length range. With a longer version of the mixing zone it decreases again.

The selected length of a respective mixing element or mixing zone can also be dependent on the type of the respective chemical or additive or the physical state. The length Li is preferably extending in the main flow direction extending axial cylindrical bore of the first mixing zone is equal to k × (D ₂ / Di), wherein the constant factor k is from that in the mixing element to be metered chemical or additive, and can assume values in particular, in a range between about 20 to about 180. In the metering of gases larger values are allowed for the factor k in order to introduce the number of maximum necessary radial bores (exit surface) in the cylindrical wall of the mixing element, whereby the introduction of a respective gas itself further increases the turbulence in the mixing zone becomes.

If the throttle device comprises a valve, for example a pinch valve, then this may expediently be detachably connected in a separate housing, for example by means of a flange connection, to the base section comprising the at least one mixing and / or reaction zone. The particular pneumatically or hydraulically operated valve can be an elastomer hose or a

Cuff made of an elastomer which is arranged, for example, in an encapsulated valve body or housing below or after the last mixing zone. The housing of the nozzle arrangement and at least the housing of a pressure chamber associated with the pinch valve can with respect to the

Dimensioned requirements of the pressure range and in particular designed in two-shell construction to obstruct the cuff therein. The

Pressure chamber housing can also be designed as a separate component and with the Housing of the nozzle assembly in the usual way, for example by means of screw, flange connection, etc., be connected. For example, the pressure chamber housing can be designed with flange connections on both sides. If the pressure in the interior of the valve body increases relative to the pressure inside the elastomer tube, the tube or sleeve is compressed and changes the flow of the medium through the tube or the sleeve. Thus, the opening or the gap width of the sleeve can be adjusted pneumatically or hydraulically variable depending on the pressure.

The pressurization of the valve housing can be done for example with filtered or oil-free compressed air or water. The flexible elastomer hose or

Cuff can be conveniently closed completely. By a differential pressure supply, for example in a range of about 0.5 to about 30 bar, preferably in a range of about 1 to 3 bar above that of the

Elastomer quality dependent medium / operating pressure in the pinch valve housing, the pinch valve can be closed, for example. This creates, for example, a lip-shaped closing image. As soon as the pressure in the interior of the encapsulated valve body is reduced or the pressure supply is interrupted and the pinch valve housing is vented, the pinch valve sleeve opens completely back to its original position due to its rebound resilience

Diameter. Due to the rebound resilience of the cuff and the

Medium pressure is guaranteed after opening a free cross-section. The

Movement of the cuff when closing and opening prevents deposits from accumulating on the cuff wall. Solid particles in the medium to be dosed are enclosed when closing the sleeve, so that the tightness of the valve is ensured. As a result, a very low-maintenance and especially in the dosage of fluid media tight operation can be ensured. In addition, an automated admission of such a pinch valve is conceivable for example, a pressure switch between the pinch valve and a

Pilot valve may be provided with which the opening pressure and closing pressure of the cuff can be queried. For the shortest possible opening time

can ensure a quick exhaust valve directly on the example

Air connection of the housing of the pinch valve to be connected.

The adjustment of the gap width of the nozzle can also be done in other ways. Thus, the gap formed in the sleeve, for example, mechanically deformed by means of one or more adjusting elements or even completely closed. In this case, these adjusting elements can be adjusted for example by means of manually, electrically, pneumatically or hydraulically driven adjusting devices. It can be applied to all commonly used in pinch valves methods for deformation of the crimp sleeve. The use of a pinch valve brings next to the possibility of a

full shut-off function, whereby the nozzle can be completely separated from the rest of the process stream, in particular the advantage of depending on the area of the opening of the squeeze sleeve change of

Flow velocity in the region of the nozzle outlet opening with it. In this way, the flow velocity from the nozzle arrangement into the process flow can be set variably. Of particular advantage is that the optimal

Speed ratio between the process stream and dosing flow can be variably adjusted and applied by means of the adjustable outlet opening. In particular, the sleeve can be made of different elastomers and adapted to the media properties such as pressure, temperature, but also other environmental criteria. Depending on the media properties and the pressure range, the sleeve can be made, for example, at least partially of natural rubber, neoprene, EPDM, Viton, silicone, nitrile, butyl, hypalon, etc.

be executed. In addition, the cuff materials used with Teflon or other coating materials. Preferably, the cuffs used, in particular made of an elastomer, are made with an inner fabric which preferably contains plastic fibers, for example nylon.

The inner contour of the particular made of an elastomeric sleeve can be designed differently, it may be cylindrical or conical, for example. Advantageously, the inner contour of the sleeve is designed so that a variable adjustment of a flow velocity in the reproducible

Exit range of the nozzle assembly of, for example, up to 30 m / s can be achieved. The outer contour of the sleeve can in particular be chosen so that a reproducible throttle is obtained.

An advantageous embodiment further consists in concentrating at least two streams in the mixing zone and mixing them together in the outflow in the mixing zone, wherein the outlet opening from the mixing chamber can be narrowed or closed by a throttle of the type described.

The inventive method and the nozzle assembly according to the invention are not limited to the dosage of liquid chemicals or additives. Rather, such embodiments or embodiments are conceivable in which in the nozzle arrangement in addition to eg liquid chemicals, a gas such as CO2, and for example hydrated lime, for example as a suspension (milk of lime, slurry of calcium hydroxide in water) or as lime water, reacted become. The solubility of calcium hydroxide (Ca (OH) ₂₎ in water is only 1, 7 g / l at 20 ° C, wherein the solubility decreases with increasing temperature. Preferably, therefore, a lime milk suspension is used, which is a much higher

Concentration in a range of, for example, about 30 to about 150 g / l of Ca (OH) ₂ . However, it is also conceivable, for example, the use of a high purity aqueous solution of hydrated lime, in a by the mixing and Reaction nozzle arrangement provided mixing space or mixing zone is reacted with CO2.

Also, in the nozzle assembly, for example, carbonated water may be brought in reaction with a slurry of lime (milk of lime) or an aqueous solution of hydrated lime.

In the production of lime from hydrated lime (Ca (OH) ₂ ), the suspension can be adjusted immediately to the use concentration. The

However, use concentration can also be adjusted, for example, directly in the mixing and reaction nozzle arrangement prior to contact with the CO2 by mixing in another dilution fluid in an upstream mixing zone.

When using lime milk, it may be advantageous if in the relevant feed to the nozzle assembly, a filter is preceded by the insoluble constituents are retained to exclude a blockage of the dosing. With a dosage of lime water can be dispensed with filters. When using lime milk, the flow rate should in particular not fall below 1, 0 m / s and preferably be greater than 1, 5 m / s. Especially with line lengths of the feed to the nozzle assembly, which are greater than about 20 m, the dosage of lime from a loop system is advantageous to exclude deposits in the piping system.

When using hydrated lime suspension (lime milk) special requirements are placed on the particle size distribution and particle size, since these parameters significantly influence the reactivity of the milk of lime. The

Grain size distribution should advantageously be as homogeneous as possible in order to allow the precipitation of calcium carbonate achieved in the reaction with carbon dioxide to proceed efficiently. Preferably, a hydrated lime (Ca (OH) ₂ ) should be used, whose homogeneous grain spectrum consists of many small particles, as the Reaction rate is essentially influenced by the particle size.

Particularly advantageous are those embodiments or embodiments, the method according to the invention and the nozzle arrangement according to the invention, in which there is a precipitation reaction in the nozzle arrangement, for example by the reaction of milk of lime with carbon dioxide. In this case, the precipitated calcium carbonate produced in this way can advantageously by means of another

Fluid flow, in particular of the injection stream, and / or the aqueous phase of the milk of lime are metered into the process stream. By means of the nozzle arrangement, the precipitation reaction and the metering into the process stream can take place simultaneously. In addition, at the same time, by means of one and the same nozzle arrangement,

In particular, further fluid chemicals or additives are metered into the process. It is particularly advantageous if a particular T-shaped combination of the respective reactants takes place in the nozzle arrangement and thus at least one mixing zone is formed, wherein the dwell or reaction time can be set by the geometry of the corresponding zone.

For example, in the application of CO ₂ , a corresponding

Merging be realized in a reaction and mixing zone by a plurality of particular radial holes preferably small diameter.

It is of particular advantage that at least one primary precipitation reaction of the calcium carbonate takes place outside the process stream or the constant part of the paper machine in the mixing and reaction nozzle arrangement, so that the process of the precipitation reaction can be influenced by the choice of the injection medium. Is used as an injection medium, for example, process water without Fiber constituents, for example filtered flotate or filtrate or fresh water, calcium carbonate is provided due to the precipitation reaction in the nozzle assembly and this metered into the process stream. Used as

Injection medium, the pulp suspension itself, so for example, a partial fluid flow as injection stream, the precipitation reaction takes place on the pulp contained in the partial fluid flow already in the mixing and

Reaction nozzle arrangement.

In particular, by means of the mixing and reaction nozzle arrangement

Various forms of application of calcium carbonate are provided:

1) dosing of a precipitated in the mixing and reaction nozzle assembly on the fibers of the partial fluid flow calcium carbonate when using a partial flow of the pulp suspension as an injection stream,

2) dosing of a precipitated calcium carbonate by means of the mixing and reaction nozzle arrangement using a fiber-free injection stream, for example filtrate, filtered flotate or fresh water,

3) Use of the lime suspension itself as an injection stream without further fluid and simultaneous reaction of the milk of lime with the CO ₂ in a respective mixing and reaction zone of the nozzle assembly, in particular immediately before dosing.

In particular, embodiments or embodiments of the method according to the invention and of the nozzle arrangement according to the invention are conceivable in which, for example, the pH or other parameters such as, for example, the temperature of the injection fluid are more optimal with regard to reaching Precipitation conditions in one of the precipitation reaction upstream mixing zone one and the same nozzle arrangement can be adjusted.

As already mentioned, for example, a reaction of carbon dioxide and milk of lime can already take place in the nozzle arrangement, ie outside the process stream. If the reaction takes place, for example, in a partial stream of the pulp suspension fed to the nozzle arrangement, the calcium carbonate is already precipitated in the nozzle arrangement onto the fibers of the suspension of the partial stream (in particular primary reaction) and then metered into the process stream. The reaction of lime and carbon dioxide in the mixed and

Reaction nozzle arrangement can be done much more selectively by changing the mixing conditions, as this is possible in the process stream itself. For example, the bubble size and the number of carbon dioxide gas bubbles can be adjusted by means of the bore diameter and the number of holes in the mixing zone.

During the primary reaction in the mixing and reaction nozzle assembly unreacted lime or unreacted CO ₂ can completely react with each other during a secondary reaction in the process stream. Due to the preferred geometry of the mixing and reaction nozzle assembly, the

necessary reaction time can be significantly reduced, so that the actual primary reaction or primary reaction is completed in less than, for example, 3 seconds, preferably less than 1 second. The precipitation reaction can be controlled and / or regulated, for example, via the size of the gas bubbles, whereby the efficiency is further increased.

In particular, by the decomposition of the reaction into a multi-stage

Reaction process (e.g., primary and secondary reactions) may increase the efficiency of the

Implementation of milk of lime and CO _{2 can be} significantly increased. In addition, the Homogeneity of the precipitated calcium carbonate can be variably adjusted by the geometry of a respective mixing zone of the nozzle assembly and the mixing parameters. Thus, the crystal structure of the precipitated calcium carbonate with respect to the required paper properties, for example, in terms of opacity and light scattering and the bulk, etc., can be influenced.

By means of the aforementioned multi-stage process is also a

more uniform distribution of the precipitated calcium carbonate is achieved on the pulp, whereby the optical quality properties and the retention of the thus introduced calcium carbonate are significantly improved.

The invention will be described below with reference to embodiments

Referring to the drawing explained in more detail; FIG. 1 is a schematic representation of one example of a plurality. FIG

Mixing and / or reaction zones comprising basic portion of an exemplary embodiment of a nozzle arrangement according to the invention,

Fig. 2 to 5 is a schematic representation of different, pure

exemplary profile shapes of a crimp tube,

Fig. 6 is a schematic representation of an exemplary

Embodiment of a nozzle arrangement according to the invention with a throttle device comprising a pneumatically or hydraulically adjustable pinch valve,

Fig. 7 is a schematic representation of an exemplary

Embodiment of a nozzle arrangement according to the invention with a mechanically adjustable pinch valve

comprehensive throttle device, wherein the pinch valve is shown in the open state, and Fig. 8, the nozzle assembly of FIG. 7, wherein the pinch valve is reproduced in the present case, however, in the fully closed state.

Fig. 1 shows a schematic representation of a plurality of mixing and / or

Reaction zones 10-i _, 10 ₂ comprising base portion 12 of an exemplary

Embodiment of a nozzle assembly 14 according to the invention for introducing chemicals and / or additives into a process stream 16 (see also Fig. 6 to 8) of a manufacturing process, which may be in particular a process for producing a fiber or nonwoven web. In this case, a respective mixing and / or reaction zone 10-i, 10 ₂ at least two to be mixed and / or chemically reacting with each other media 28, 54 can be fed. As can be seen in particular from FIGS. 6 to 8, the nozzle arrangement 14 may comprise a throttle device 20 arranged in the region of the nozzle outlet opening 18.

In the present case, the nozzle assembly 14 includes, for example, two in

Main flow direction 22 considered successively arranged mixing and / or reaction zones 10-i, 10 _second

As can be seen from FIG. 1, the main flow cross-section of the nozzle arrangement 14 may have a turbulence-generating cross-sectional widening 24 in the region of at least one mixing and / or reaction zone 10. in the

In the present case, such a cross-sectional widening lies in

Main flow direction 22 considers both in the region of the front end of the first mixing and / or reaction zone 10i and in the region of the front end of the second mixing and / or reaction zone 10 ₂ . As can best be seen again with reference to FIGS. 6 to 8, the nozzle arrangement 14 can be supplied with an injection stream 28 via a nozzle inlet opening 26. The nozzle arrangement 14 may in particular comprise at least one mixing and / or reaction zone 10, which comprises at least one fluid chemical or

Additive stream 50 is supplied. In particular, it is also possible that at least one mixing zone 10, at least one dilution fluid stream 48 is supplied. In particular, those embodiments of the nozzle arrangement 14 are conceivable in which at least one mixing zone 10, at least one gas stream is supplied.

If, as shown in Fig. 1, in a respective zone 10, turbulence generated, for example by a cross-sectional widening 24 of the

Main flow cross-section of the nozzle assembly 14, so for example, a respective chemical or additive stream 50, gas flow and / or

Dilution fluid stream 48 are expediently in the range of maximum turbulence of the zone 10, introduced.

Advantageously, such embodiments are also conceivable in which at least one zone 10 of the nozzle arrangement 14 is at least one

Chemical stream 50, in particular gas stream supplied and in this zone 10, with the chemical in question and at least one other reactants, a chemical reaction, in particular precipitation reaction is brought about. In this case, the precipitate in the respective mixing or reaction zone 10, for example supplied to the nozzle assembly 14 via the nozzle inlet opening 26

Injection stream 28 are mixed. However, the chemical reaction, in particular precipitation reaction in the respective zone 10, can also be brought about, for example, with at least one further reaction partner which is contained in an injection stream 28, in particular partial fluid flow, supplied to the nozzle arrangement 14 via the nozzle inlet opening 26. The nozzle assembly 14 may comprise a cylindrical housing 30 in which one or more, the zones 10, forming mixing elements are located, each comprising a cylindrical body 32, whose outer peripheral surface with a

annular recess 34 is provided, in which bores 36 are introduced in the radial direction, which open into the main flow direction 22 extending central axial bore 38 of the mixing element. The annular recess 34 of the respective mixing element is connected through the wall of the housing 30 with at least one media feed. The individual mixing elements are sealed by means of seals 40 against each other and the housing wall. The angle between the axial bore 38 and the radial bores 36 is

preferably 90 °.

As can be seen in particular with reference to FIG. 1, the cylindrical

Diameter D _{3 of} the inner cylindrical, in particular circular cylindrical

Cross sectional area (axial bore) 38 of the first mixing zone 10i forming

Mixing element smaller than the cylindrical diameter D _{3 of} the inner cylindrical, in particular circular cylindrical cross-sectional area of the subsequent, the second mixing zone 10 ₂ forming mixing element. The step-like enlargement of the rotationally symmetrical cross-section of the cylindrical flow channel or axial cylindrical bore 38 resulting from the succession of the individual mixing elements leads to the following effect:

The increase in the flow cross-section of the cylindrical bore 38 causes a return vortex 42 in the flow (see FIG. 1). Especially in the boundary layers of this vortex 42, there are large shear stresses that cause turbulence, by means of which an efficient mixing of the introduced media is achieved in the mixing element. That through the

Cross-sectional expansion 24 forming shear field is used here for the interference of the relevant medium, in particular fluid chemical, or gas. The dosage of the respective fluid flow or the arrangement of the holes 36 for the application of the respective media in question preferably takes place in the region of the maximum turbulence of the corresponding mixing element.

The injection stream 28 is first conducted in the cylindrical inner cross section of the first mixing zone 10i forming mixing element and then in a

Stages jump in which the second mixing zone 10 ₂ forming second mixing element continued. The injection stream 28 can be guided via a first section 44 of the base section 12 into the first mixing zone 10i. The diameter of the inner cylindrical cross section of the portion 44 is denoted by Di, the diameter of the inner cylindrical cross section of the first mixing zone 10i with D ₂ and the diameter of the inner cylindrical cross section of the second mixing zone 10 ₂ with D ₃ . The ratio between the diameter D ₂ and the diameter Di, that is, the increment ratio D ₂ / Di, where D _{2 is} the diameter after the increment and Di is the diameter before the increment, is advantageously in a range of about 1.1 to about 5.0, more preferably in a range of about 1.1 to about 2.0, and preferably in a range of about 1.2 to about 1.5.

The length Li of the first cylindrical mixing zone 10i is dependent on the

step-like extension and is advantageously in a range of 10 to 50 times the length (D ₂ - Di) / 2. The turbulence is greatest in this length range. With a longer execution of the mixing zone, the turbulence decreases again. With regard to the design of the length of the mixing element, this is also dependent on the type of chemical or state of aggregation. The length Li of the first cylindrical mixing element is advantageously equal to kx (D ₂ / Di). Here, the constant factor k is dependent on the metered in the mixing element

Chemical or additive, and may advantageously assume values in a range between about 20 and about 180. For the metering of gases, greater values are permissible for k in order to be able to introduce the maximum number of generally radial bores (exit surface) required in the cylindrical wall of the mixing element, whereby the introduction of the gas itself further increases the turbulence in the mixing zone.

As described in more detail below, a respective zone 10 can also be provided as a reaction or mixing and reaction zone, in which at least two

Reactant cause a chemical reaction, especially precipitation reaction. In particular, a T-shaped combination of at least two media and in particular of respective reactants in the nozzle assembly 14 is advantageous in order to form at least one mixing zone, wherein through the

Geometry of the corresponding zone the dwell or reaction time can be adjusted. For example, in an application of CO2 can for a

corresponding merging in the reaction mixing zone, for example, be provided a plurality of generally radial bores preferably small diameter.

As can be seen again in particular with reference to FIGS. 6 to 8, the

Nozzle arrangement 14 also comprise a throttle device 20 arranged in the region of the nozzle outlet opening 18, the flow characteristics of which can be varied variably and / or which can be solved to enable a respective exchange with another flow device having a different flow characteristic

Base section 12 is connected. In this case, the throttle device 20

For example, be releasably connected to the housing 30 of the nozzle assembly 14.

The nozzle outlet opening 18 can via the throttle device 20th

expediently also be completely closable, so that the nozzle assembly 14 can be completely separated from the process stream 16. As can be seen in particular with reference to FIGS. 2 to 8, the

Throttle device 20 comprise a valve designed in particular as a pinch valve with preferably at least one in particular pneumatically or hydraulically acted upon flexible hose or flexible sleeve. Here, FIGS. 2 to 5 show, by way of example, a schematic representation of different advantageous profile shapes of a suitable squeezing tube 46.

For example, the squeeze tube 46 according to FIG. 2 can have a groove profile.

In the illustrated in Fig. 3 embodiment, the crimp tube 46 has a profile shape in the manner of a double cone with respect to the inner cross section.

According to FIG. 4, the crimping tube 46 may also have, for example, a continuous cylindrical inner profile.

Fig. 5 shows an exemplary embodiment, according to which the crimp tube 46 has an inner profile in the form of a single cone. By means of the pinch valve of the throttle device 20, which is in the range of

Nozzle outlet opening 18 and in particular between this and the at least one mixing and / or reaction zone 10, comprising the base portion 12 may be arranged (see Fig. 6 to 8), the mixing and / or reaction nozzle assembly 14 is suitably completely against the process stream 16th be shut off. The pinch valve, which may consist at least partially of a deformable sleeve, can be adjusted in any position between fully open and closed. The outflow velocity in the region of the nozzle outlet opening 18 can be adjusted by means of the variably variable cross section in the area of the nozzle outlet or via a corresponding change in the nozzle outlet

Cross-sectional area of the sleeve can be variably adjusted. This can be the Flow rate in the region of the nozzle outlet opening 18 are set independently of the chemical or additive concentration and also at a constant metered amount of the chemical or additive. By setting the optimum flow rate, for example, one in the mixing and / or

Reaction nozzle diluted retention means in the region of the nozzle outlet opening 18 may e.g. the flocculation characteristics are favorably influenced.

As can be seen with reference to FIG. 6, the throttle device 20, for example, a pneumatically or hydraulically adjustable pinch valve with a

Crimp tube or sleeve 46 and an associated pressure housing 48 include.

As already mentioned, the nozzle assembly 14 via a

Nozzle inlet opening 26, an injection stream 28 are supplied, which may be, for example, a partial fluid flow. The first mixing zone 10 i, for example, a dilution fluid stream is supplied as a mixed stream 48. The second mixing stage 10 ₂ , for example, a chemical or additive stream 50 are supplied. In principle, however, only one or more than two zones may be provided, wherein, as already mentioned, these zones may each be mixing and / or reaction zones. As already mentioned above, a respective mixing and / or reaction zone 10, for example at least one chemical stream, at least one additive stream, at least one gas stream and / or at least one dilution fluid stream can be supplied.

As can be seen from FIG. 7, the throttle device 20 can be used

For example, a mechanically adjustable crimp sleeve or

Sheath 46 include. The squeezing sleeve 46 can be acted upon here, for example, by a mechanical adjusting element 52 which is adjustable, for example, transversely to the main flow direction 22. The crimp sleeve 46 is in the present case played in the open state.

The basic section 12 of the nozzle arrangement 14 comprising the mixing and / or reaction zones 10 can, in particular, again be designed as described with reference to FIGS. 1 and 6. Corresponding parts are assigned the same reference numerals.

Fig. 8 shows the nozzle assembly 14 of FIG. 7, wherein the squeeze sleeve 46 is reproduced in the present case, however, in a fully closed state. Corresponding parts are again assigned the same reference numerals.

Reference List Mixing and / or reaction zone

base portion

nozzle assembly

process stream

Nozzle outlet opening

throttling device

Main flow direction

Cross-sectional widening

Nozzle inlet opening

injection current

cylindrical housing

cylindrical body

annular recess

radial bore

central axial bore

poetry

returning vortex

part Of

Crimp tube or cuff mixed flow

Chemical or additive flow mechanical actuator

medium

Claims

claims

1 . Method for introducing chemicals and / or additives into a process stream (16) of a production process, in particular a process for producing a fiber or nonwoven web, by means of a nozzle arrangement (14),

characterized in that

a nozzle arrangement (14) with at least one mixing zone (10,) and a throttling device (20) arranged in the region of the nozzle outlet opening (18) is used, the flow characteristic of which can be variably changed and / or the variability of the flow characteristic in the region of the nozzle outlet opening (18 ) against each other

Throttling device (20) is interchangeable with a different flow characteristic,

in a respective mixing zone (10,) in each case at least two media are mixed together and

in order to set different flow velocities of the mixed flow emerging from the nozzle outlet opening (18) and to be introduced into the process stream (16), the respective flow characteristics of the throttle device (20) are changed respectively

Throttle device (20) is replaced by a throttle device (20) with a different flow characteristic.

2. The method according to claim 1,

characterized in that

a nozzle arrangement (14) with a plurality of mixing zones (10-i, 10 ₂ ) arranged successively in the main flow direction (22) is used.

Method according to claim 1 or 2,

characterized in that

the nozzle assembly (14) via a respective nozzle inlet opening (26) at least one injection stream (28) is supplied.

Method according to one of the preceding claims,

characterized in that

at least one in particular fluid chemical and / or at least one additive stream is supplied to at least one mixing zone (10,).

Method according to one of the preceding claims,

characterized in that

at least one mixing fluid stream (10,) is supplied to at least one mixing zone.

Method according to one of the preceding claims,

characterized in that

at least one gas stream is supplied to at least one mixing zone (10, 10).

Method according to one of the preceding claims,

characterized in that

in a respective mixing zone, the mixing of the respective media promoting turbulence can be generated.

Method according to claim 7,

characterized in that

the turbulences in a respective mixing zone (10,) are generated at least partially by a cross-sectional widening (24) of the main flow cross-section of the nozzle arrangement (14).

9. The method according to claim 7 or 8,

characterized in that

at least one chemical stream, at least one additive stream, at least one gas stream and / or at least one dilution fluid stream is introduced into the region of maximum turbulence of the mixing zone (10, 10).

10. A method for introducing chemicals and / or additives into a process stream (16) of a production process, in particular a process for producing a fiber or nonwoven web, by means of a nozzle arrangement (14), in particular according to one of the preceding claims,

characterized in that

at least one zone, in particular mixing zone (10,), the

Nozzle assembly (14) at least one chemical stream, in particular gas stream, fed and in this reaction or mixing and

Reaction zone (10,) with the chemical in question and at least one other reactants a chemical reaction, in particular precipitation reaction is brought about.

1 1. Method according to claim 10,

characterized in that

the precipitate in the respective zone (10,) one of the

Nozzle assembly (14) via a nozzle inlet opening (26) supplied injection stream is mixed.

12. The method according to claim 10 or 1 1,

characterized in that

the chemical reaction, in particular precipitation reaction, in the respective zone (10, 12) is brought about with at least one further reaction partner, which in one of the nozzle arrangement (14) via a Nozzle inlet opening (26) supplied injection stream (28), in particular partial fluid flow is contained.

13. nozzle arrangement (14) for introducing chemicals and / or additives into a process stream (16) of a production process, in particular a process for producing a fiber or nonwoven web, in particular for carrying out the method according to one of the preceding claims,

characterized in that

the nozzle arrangement (14) has a base section (12) with at least one

Has mixing and / or reaction zone (10-i, 10 ₂ ), the at least two mixed with each other and / or chemically reactable media can be supplied, and preferably in the field of

Throttle device (20) arranged in the nozzle outlet opening (18) whose flow characteristics can be variably changed and / or which are connected to the

Enabling a respective exchange for another

Throttle device (14) with a different flow characteristic releasably connected to the base portion (12) is connected.

14. nozzle arrangement according to claim 13,

characterized in that

it comprises a plurality of mixing and / or reaction zones (10-i, 10 ₂ ) arranged one behind the other in the main flow direction (22).

15. nozzle arrangement according to claim 13 or 14,

characterized in that

the main flow cross section of the nozzle arrangement (14) in the region of at least one mixing and / or reaction zone (10-i, 10 ₂ ) one

Having turbulence generating cross-sectional widening (24).

16. nozzle arrangement according to one of claims 13 to 15,

characterized in that

the nozzle outlet opening (18) via the throttle device (20) is also completely closable.

17. nozzle arrangement according to one of claims 13 to 16,

characterized in that

the throttle device (20) comprises a valve designed in particular as a pinch valve, preferably comprising at least one flexible hose or flexible sleeve which can be acted upon in particular mechanically, pneumatically or hydraulically.