DE4206521A1 - Drying wetting, washing and/or cleaning agent or component - Google Patents

Abstract

In drying wet wetting, washing and/or cleaning agents (IA) and/or components (IB) of these and their aq. solns. and/or suspensions with superheated steam (II), which is recycled after removing the fraction of water vapourised in the drying stage, (II) leaves the drying zone at a temp. of min. 150 (esp. min. 180) deg.C and the internal pressure of the (II)-filled system is at or esp. above normal to prevent air entering, e.g. at sites of damage, the internal pressure pref. being under ca. 50 mbar gauge. (I) may be zeolite cpds., esp. NaA zeolite. Pref. the starting material is spray dried through nozzle(s), e.g. with rotating discs, and the inlet temp. (Ti) of (II) is min. 250 deg.C. To produce high bulk density, Ti is min. 325, esp. min. 350 deg.C and the amt. (Wv) of water vapourised is min. 300 (esp. min.) 400 kg/m2.h w.r.t. the cross-section of the drying zone. To produce the bulk density, Ti is max. 280 deg.C and Wv is 100-250 kg/m2.h. In both cases, the (II) throughput is 1.0-4.0 (pref. 1.5-3.0, esp. 1.8-2.5) m3/m2.s. Additives (III) may be incorporated in the incompletely dry prod. to bind the residual water (partly), so that the dry prod. has storage-stable bulk and free-running property and (III) pref. are (partly) added to the aq. soln. or suspension before drying.

Description

The invention relates to a process for the production of bulk and free-flowing granules of materials or mixtures of materials, which as wetting, washing and / or cleaning agents and / or for use are suitable in such agents from their aqueous solutions and / or suspensions by fluidized bed spray granulation in one are called fluidizing gas in the range of normal pressure.

To generate particles from an initially liquid product, ie from solutions or suspensions, come in technical application in particular spray drying, spray drying with integrated Fluid bed agglomeration and fluid bed spray granulation in question. Usually is used in the production of granules aqueous preparations of valuable materials of the type mentioned for decades on a large industrial scale the spray skirt  used. Hot air or Gemi are used as the drying gas flow air and hot combustion gases. Textile washing powder as well as recyclables and mixtures for the production of Textile detergents in pourable and free-flowing powder form are used in so-called spray towers usually in the area of the ambient pressure in countercurrent, more rarely in cocurrent mode, on an industrial scale won.

Also the use of fluidized bed spray granulation for production detergent granules are known from the prior art (Uh lemann in Chem.-Ing.-Tech. 62 (1990) No. 10, pp. 822-834 and EP-B 1 63 836). In this process, which is used to produce powder However, wetting agents, detergents and cleaning agents are used much less frequently leads, solid particles are in an upward direction Gas flow kept in suspense. The parties are in this state separate from each other and so when spraying liquid in the fluidized bed is accessible to the spray drops all around. In addition fin in this state there is an intensive heat and mass exchange between the solid particles and the gas flow instead.

Now when a floating particle is hit by a spray drop the liquid product of the spray drop is distributed on the solid surface by spreading. The intense warmth and fabric exchange with the surrounding gas flow leads to drying and Solidification of the liquid film. By multiple spraying, Spreading and solidification, the particle grows onion-like. The part Chen with the desired grain size is compact and also almost round.

In the fluidized bed spray granulation of aqueous preparations The substances mentioned at the beginning become like hot spray drying air worked as a fluidizing gas. From EP-B-1 63 836 fer ner called the use of nitrogen gas.  

The advantages of the drying process using hot air among other things, the dry gas includes any available gaseous phase the possibility to work in open systems can, the disposal of the moisture-laden hot gas phase is technically possible by releasing it into the outside air chen. Intensive physico-chemical studies on the Ab course of the drying process have also shown that the Drying with hot air is comparatively milder even when used Hot gas temperatures run effectively and quickly. The drying process on wet particle sets largely independent of the The temperature of the hot gas used is comparatively never low temperatures - for example at temperatures of the particles of around 40 ° C - and settles under comparatively slower Increasing the particle temperature up to the boiling range of the water under normal pressure. Overall, the drying process runs in Hot air quickly and especially in the last drying stages effective, so that the recyclable materials become free-flowing goods when they dry are exposed to a comparatively mild temperature load.

Straight from the disadvantages and limitations of this type of procedure for the subject of drying addressed by the invention of recyclables or mixtures of recyclables from the areas of Tex Detergent and / or detergent is an example of that the following points: Many of these recyclables are ins especially in the case of organic components - sensitive to oxidation. The treatment with hot air can be especially in the higher temperature rich lead to damage. The drying up pure or largely organic materials, e.g. B. of surfactants based on natural substances, creates significant problems from fire or even explosion Risk of dry goods. Important recyclable components, in particular Nonionic surfactants in the detergent range, show a more or less strong pluming tendency, d. H. on the transition from organic aerosols to  the steam-laden exhaust air from the spray towers. Overall he exists increased risk of environmental pollution due to the large quantities of processed processed aqueous, solid and gaseous material and auxiliary materials fabrics. Considerations for recycling the drying gas flow have none in the commercial application of this process reaching precipitation.

In fluid bed drying, it is also known instead of Use hot air as the drying gas for hot steam (Gehrmann, Chem. Ing.-Tech. 62 (1990) No. 10, p. A 512-A 520). Here are special low emissions (waste water, exhaust air), in which the driven vapors are condensed. According to the state of the art However, this method is only for those who are relatively insensitive to temperature Products such as B. lignite or sewage sludge can be used. As an area of application is also called the drying of paper pulp. in the same document is used to reduce emissions when drying use of vacuum drying recommended, but at the same time also on the difficulties with continuous operation of these devices with free-flowing bulk goods pointed out.

Even when drying temperature-sensitive products in steam fluidized bed dryers encounter problems. The drying speed speed in the temperature range around 150 ° C is for superheated steam namely significantly lower than for hot air. Only the increase in Working temperature to 250 ° C brings the drying area closer speed. A drying of the materials of the beginning ten way in usual residual moisture contents with an acceptable dry duration can be used when using superheated steam Drying gas can therefore only be reached with such high working temperatures Chen, where a no longer acceptable temperature damage to the Good use occurs.

The invention is therefore based on the object of the method of to improve the type mentioned so that it is emission-free and free of loaded wastewater can be carried out without the large-scale application of the process a deterioration in quality tion of the granules obtained occurs.

This object is achieved in that with heated water vapor works as a fluidizing gas, thereby the granu lat before its exposure to thermal effects from the granu lator discharges and the storage-stable bulk and pourability of the partially dried product in this way, if necessary by adding Set for binding limited amounts of water in mixed mixtures components and / or post-treatment ensures and that in closed system works with a steam cycle flow, which is the evaporated water portion of the feed as a partial stream withdraws and supplies the given thermal energy again. The Ener Pouring can occur outside of the drying container due to overheating of water vapor and / or within via integrated heat exchangers respectively.

In the earlier application DE-A 40 30 688 there is a method for winning of such finely divided, solid pourable or free-flowing value substances or mixtures of substances for wetting, washing and / or cleaning described from their aqueous preparations, being overheated ter steam used as a drying hot gas stream and thereby drying of the particulate material before it is endangered thermal action is canceled. If necessary the storage-stable bulk or free-flowing properties of such partially dried goods by adding such a mixture components ensured that bind limited amounts of water are qualified. In addition to or instead of this measure, a Post-treatment for homogenizing the residual moisture content in the parti kular good and / or its subsequent drying under preserving materials Conditions are connected.  

However, the older application describes the production of granules spray drying used. A fluidized bed drying is only optional before the aftertreatment of the dried goods seen.

The invention described below relates to a targeted Ausge Organization of this procedure from the earlier application mentioned. Out For reasons of completeness of the disclosure of the invention is hereby the disclosure of this earlier application expressly also for Ge subject made the present disclosure of the invention.

In this context it should be borne in mind that the practical experience in the use of drying processes Use of superheated steam as a drying gas be very are limited, although this technology has inherently been the ses Century is known and repeated in the literature is written. The older patent application DE-A 40 30 688 settles with the relevant state of the art in print apart. On this information from the older application, be here referenced and only be the following publications named, which in turn has extensive bibliographies on this Field of work included: A. M. Trommelen et al. "Evaporation and Drying of Drops in Superheated Vapors "AIChE Journal 16 (1970) 857-867; Colin Beeby et al. "STEAM DRYING" Soc of Chem Eng, Japan, Tokyo (1984), 51-68 and W. A. Stein "Calculation of the Evaporation of Liquid from moist products in the spray tower "Process engineering 7 (1973) 262-267.

A fundamental one for understanding the invention Difference between drying with hot air and drying with superheated Water vapor is striking: when working with the hot air flow the drying process starts at low product temperatures  effective one. The water depletion is so out characterizes that when the material temperature of about 100 ° C is reached Drying is almost complete. For example, up to about 90% of the total water available at this time already carried out from the drop. The course looks completely different the drop temperature when using superheated steam. By condensate sation of the superheated steam on the cooler feed and delivery of the Heat of condensation on the material to be dried finds a spontaneous one Heating of the aqueous drop to the boiling point of the water under working conditions, i.e. when working under normal pressure to temperatures of around 100 ° C. This boiling temperature is called Min minimum temperature during the entire drying period in the crop maintain. The respective loading of the aqueous phase with the leads to winning dry substances - depending on the dry Degree of drop - to individual deviations in tempera upward to an earlier or later point in time.

In the process according to the invention, ge is accepted with conscious acceptance some restrictions regarding the drying result in the end product of the many advantages of hot exchange air through superheated steam in the fluidized bed spray granules tion method precisely in the tempera affected according to the invention door-sensitive items to be dried. As an essential ches element provides the invention here, residual moisture in the dry material tolerated, which - depending on the individual case - definitely can be considerable, but at the same time either given if necessary, auxiliary materials to be used and flowability of the granular material thus dried ensure and / or post-treatment z. B. a dressing gown provision. The auxiliaries can, as in the following is still described, in turn selected recyclables for the planned use or inert substances. According to the ge  the compliance with the quality standards of the well-known com complex requirements for the More affected by the invention mixtures of substances based on organic and inorganic mixture com components - for example textile detergents - without loss of quality, however, while realizing the benefits of overheating drying Steam. Oxidation processes on endangered components of the Wetting agents, detergents and cleaning agents are prohibited; Fire and Ex explosion risks are switched off. Since the drying steam in Circulation is dispensed with, the delivery of unwanted components into the ambient air. Only that from the material to be dried The resulting steam partial flow is discharged and requires Reini supply. Any shares of good that are carried along are utilized. Other technological advantages for the interpretation of the corresponding Appropriate facilities can be used.

The energy from the steam circuit outside the fluidized bed The entry can be made in any known form the. However, indirect heat transfer is preferred. As an an example the use of tube bundle systems should be mentioned, on the one hand from heating gases of any origin and on the other hand - but separately of these heating gases - of the steam flow to be heated be flowed through.

In a particularly important embodiment of the invention, the This indirect energy input into the steam cycle flow by means of egg nes or more integrated burners with indirect heat transfer the steam flow, with the hot side on the burner side Combustion gases are introduced directly into the heat exchanger be integrated into the steam cycle stream. The tempera The combustion gases can be in the range of, for example about 400 to 1,000 ° C and especially in the temperature range of about 650 to 960 ° C. For optimal heat utilization and thus for  It may be appropriate to reduce the cost of the overall process Proportionate, preferably as far as possible, recycling To provide flue gases. For example, at least 30% by volume and preferably more than 40 vol .-% of the hot flue gases after the Leaving the integrated heat exchanger in the circuit too far energy recovery. Preferably the amount of flue gas circulation is more than 60 vol% and often in the range of about 70 vol .-% of Ver supplied combustion gases. All the usual Brennga are used to operate the burner se, in particular natural gas or comparable lower hydrocarbons Fe or hydrocarbon mixtures and / or hydrogen are suitable.

In the process according to the invention, the superheated steam is mainly carried out Heat energy via internal or external heat exchangers, the superheated steam serves as the transmission medium. By the verver casual and total exclusion of pollutants, especially acid Substance and carbon dioxide in the drying gas are undesirable oxidative Attacks on the goods to be dried are excluded, as is education of carbonate salts or carbonate deposits, which are mostly in the basi the valuable materials of the work area affected here at work drying gases containing flue gas are unavoidable. The use of heat exchangers integrated in the fluidized bed additional heating enables particularly effective warmth transmission and allows a significantly lower steam temperature than the sole heating by introducing superheated steam to the to obtain the same residual moisture, so that the thermal stress of the goods to be dried is low. This process variant is suitable is particularly suitable for items with moderate temperature sensitivity ease. When drying thermally sensitive materials and Mixtures of recyclable materials are advantageously only external heat to use exchangers, with shorter residence times than with im Fluid bed integrated heat exchanger sets.  

According to the invention in a closed system with a steam circulating current worked, which the evaporated water portion of the one set goods is withdrawn, especially during drying The amount of energy released is returned to the circulating current becomes. The stripped water vapor partial stream is after cleaning of carried parts of the input material in an important off leadership form as service steam otherwise used after ge if desired, pressure and temperature of this partial steam flow have been adapted to the conditions required there. In a it is another embodiment of the method according to the invention expedient, at least a portion of this stripped steam part to condense current. The resulting aqueous liquid phase is preferably after concentration together with those before lying circles of recyclable material for the preparation of the drying aqueous solutions and / or suspensions used.

It is also preferred with internal pressures of the steam-filled system in Range of normal pressure worked. But in particular such raised pressures in the circulatory system that, at for example, at damaged areas that never occur in large-scale plants Sometimes there are no air inlets into the steam filled Circulatory system can be prevented with certainty.

Working in the area of normal pressure enables the comparison wise complication-free operation even in large-scale plants the required high material throughputs per unit of time. Since extraneous gas, especially air, into the circulatory system filled with water vapor cannot collapse, secondary damage is the target high-quality product quality thus reliably excluded. Suitable working pressures are, for example, in the range up to approximately 150 mbar, suitably up to about 75 mbar and preferably below 50 mbar. The range from about 5 to 15 mbar system internal pressure can be  be particularly preferred. Drying with superheated steam in the The principle of the invention is of course also in the case of negative pressures, then possible, especially in the area of moderate negative pressures but an increased technical effort to ensure the end possible damage points in the circulatory system through which desired air ingress would be triggered.

What is essential in the teaching according to the invention is the omission of Setting optimal drying results by exposure to superheated steam in the process end product. Residual moisture, also quite considerable Extent, can be tolerated if in the composition of the Good things are ensured that a kind of "internal drying" such extensive binding of this residual water takes place that the guarantee storage-stable bulk and free-flowing properties of the dry goods is accomplished.

Requires the temperature sensitivity of the material to be dried or mixture of recyclable materials the retention of not inconsiderable what Amounts of water in the product of the main drying and, if necessary, the Binding of this residual water to ensure storage stability Bulk and free-flowing properties of the dry goods, so fiction used according to auxiliaries, preferably as a particulate solid body are capable of water fixation. Such fixation of Residual water can be incorporated as a crystal, for example water. But also a purely absorptive bond limited amounts of water in solid particles of those affected Possible without causing undesirable stickiness or Adhesion of the particles to one another is effected. The excipients are used in at least such a sufficient amount that despite the the residual and storage stability in the residual moisture is guaranteed.  

The auxiliary materials that bind the residual water can be in one version Form of the invention expediently the dried fresh material added immediately after its discharge from the granulator and thus be mixed intensively. In a preferred embodiment However, these auxiliaries take at least some form se, the aqueous solutions or suspensions even before the vortex Layered spray granulation added. This is possible last mentioned embodiment whenever the respective Temperaturem sensitivity of the goods to be dried such extensive drying allows the remaining residual moisture to a sufficient extent absorbed and bound by such auxiliary substances used can be.

In a preferred embodiment of the he The inventive method are used as residual water binding adjuvant corresponding materials from the area of wetting, washing and / or cleaning agents are used, which in turn are sufficiently tempe are insensitive to nature. Typical examples are crystal water-binding inorganic materials from the classes of builders Components, the washing alkalis and / or the so-called adjusting agents, e.g. B. crystal water-binding silicate compounds, in particular Zeo lithe. A particularly characteristic for textile detergents Today, the detergent-quality zeolite NaA is one game Calcium binding capacity in the range of 100 to 200 mg CaO / g - compare che the details of DE 24 12 837. Examples of crystal water Serum binding alkalis are soda or sodium bicarbonate, while Sodium sulfate as a neutral salt or adjusting agent considerable amounts can bind to crystal water. In addition to or instead of such auxiliary can bind substances with the ability to bind water of crystallization the residual water also by means of auxiliary materials or appropriate materials can be used with the ability to absorb water. It is known that known graying inhibitors on starch  or cellulose-based, textile softening aids, in particular based on inorganic, swellable silicates, but also a number of organic surfactant compounds that are solid under normal conditions can absorb significant amounts of water without using an un desired surface tack to respond to.

Depending on the temperature sensitivity of the recyclables used or mixtures of materials on the one hand and the nature and quantity of auxiliary materials used on the other hand can have considerable residual water contents remain in the dried goods without their la to endanger tannable bulk and pourability. Invention is therefore provided for drying with superheated water steam at residual water content from the fluidized bed Abort good in the range of about 1 to 20 wt .-%, the rest water contents in the range of about 5 to 15% by weight are preferred. The ranges given here refer to the weight of the material discharged from the fluidized bed. According to the invention further preferred, the proportion of this residual water that is not considered Water of crystallization is bound, preferably to a maximum of about 10% by weight limit to no more than about 3 to 4% by weight. Here too applies to the wt .-% - what was said before.

Enable the working conditions of the method according to the invention the use of high temperatures of the circulated water vapor phase in the area of drying in a fluidized bed. Will the heat brought in exclusively via the vapor phase, so are workers temperatures in the range of about 270 to 350 ° C in the water vapor phase particularly suitable. These temperature specifications refer in each case to the temperature of the fluidized bed, to optimal temp temperature of heated steam flow.

When used in the fluidized bed, the heat exchanger is integrated  the heat is mainly introduced through this heat exchanger. The Water vapor phase is used for fluidization. In this case, the preferred inlet temperatures of water vapor never significantly third, namely at 150 ° C to 180 ° C. The lower drying here speed is determined by the greater bed length and / or bed height and thus due to the longer dwell time in the drying zone compared. Depending on the temperature sensitivity of the items to be dried therefore one of the two embodiments more advantageous.

Largely energetic considerations - especially regarding the be deliberate further use of the partial steam flow to be removed - determine the proportions between the rivers to be evaporated amount of water and the amount of superheated water supplied steamy. Embodiments are possible that only one limited lowering of the steam temperature after leaving the vortex Provide beds, while in other embodiments continue Effective use of the thermal energy of water vapor up to a decrease in the steam temperature in the vicinity of the condensation temperature may be appropriate. It is also possible in itself known way to divide the fluidized bed into different zones: High and medium temperature zone and cooling zone.

A particularly interesting embodiment of the invention sees the Recovery and recovery of the heat of condensation from the Cycle of ejected water vapor. Because of the engagement Suitable steps can also be the recycling of low proportions of recyclable materials are ensured, which exceed the flow of hot steam left the primary circuit of the steam have. Here, for example, using the condensate tion heat of the discharged steam portion worked as follows will:  

In a preferably multi-stage evaporation plant is used the heat of condensation of the subtracted steam the steam concentrated condensate. The remaining concentrate is returned to the primary process circuit. In particular can this residual concentrate is to be dried by superheated superheated steam Recycled slurry are added.

If necessary, condensation from the primary cycle of discharged superheated steam if necessary falling residual gas phase loaded with the smallest amounts of recyclable material subsequent processing step - for example a scorch treatment, treatment in biofilters or in washing systems will. By such a combination of measures of a practical complete recycling of the respective partial flows and the This enables the reliable destruction of the last traces procedures in accordance with the work area concerned here are large technical production for the first time the possibility of valuable materials and value Exhaust air mixtures of substances from the field of washing and cleaning agents can be extracted free and free of loaded wastewater.

In addition to or instead of using to bind the residual water The invention further provides for qualified auxiliary substances aftertreatment the primary accumulated, partially dried granules. The Aftertreatment is realized by two technical concepts, that can also be connected to each other.

The first of these conceptions assumes that the individual Degree of drying of the particle concerned from its part size is determined. According to the invention, the drying process  canceled at a time when there were still considerable quantities of residual moisture in the goods, then an integral consideration the residual moisture content only partially meets reality. In the differential consideration of the distribution of this residual moisture It can be seen from the individual shares that the fine relationship very fine or very dry can be while the coarser good parts are still so moist, that a storage-stable bulk and pourability for the Fluid bed removed material is not yet ensured. In a important embodiment of the method according to the invention correspondingly a "post-drying" of the primary material from the vortex layer through an additional, at least one-stage after-treatment achieved step that - without the powdery material of a Ge exposure to glue - to homogenize the Moisture content over the total good regardless of the individual Particle size leads. In this way, from the still comparative wise, coarser parts of the material so much residual moisture in the fine and ultra-fine material are transferred that after this homogeneity the storage-stable bulk and pourability of the Dry goods are guaranteed without the additional off further amounts of moisture from the bulk material are required.

All procedures are necessary to achieve this post-treatment stage techniques appropriate to the moisture content of each part kel while preventing sticking of the mass compensate. Circulation and mixing are only examples here or shaking the primary product in continuous or called discontinuous processes. Can be particularly suitable an aftertreatment of the goods in a downstream, further one Be a fluidized bed.

Here, with any gases, preferably with ambient air,  worked. Oxidative material hazards and undesirable pollution Exhaust air cleaning does not occur or hardly occurs here are easy to master. Since the material to be dried is the fluidized bed with elevated temperature - usually in the range of about 105 ° C - can be removed via such a downstream moisture homogenization in a fluidized bed still a little too additional reduction in residual moisture can be achieved.

In addition to or instead of such an auxiliary measure in the Invention according to the method but also an additional drying in one or several stages are provided to further reduce the residual moisture be. It is characteristic of post-drying that here under Conditions are worked, which are the recyclables of the dry material not harm. As an example of process parameters for risk reduction are mentioned: lowering the temperature of the hot gas phase, Avoid superheated steam as a hot gas and replace it by drying gases of other origin, for example air and / or Inert gas and transition to another drying technology.

The process of fluidized bed spray granulation is based on the Growth of germs that do not occur either in the fluidized bed itself hitting, solidifying spray drops are formed, or generated by abrasion of existing solid particles, or which are fed from the outside to the fluidized bed. To ensure a continuous To ensure proper procedural conduct must be consistent Granulation conditions prevail. Remove all from the fluidized bed Granules have to be replaced by new germs. On the other hand, the exhaust gas from the fine material carried must be cleaned be inclined. However, these fine particles are also seedlings. In order to a particularly simple and economical way of balancing the Ensuring the above-mentioned particle balance is therefore preferred suggest that the escaping from the fluidized bed with the exhaust gas  Separates fines and as germs for the formation of granules special internally with the help of a arranged above the fluidized bed Dust filter in the fluidized bed. The separation of the Fines from the exhaust gas can be made with cyclones. Before but it is partial that the exhaust gas is in the head of the granulator integrated cloth filter arranged above the fluidized bed nends. This will save space in the anyway necessary Exhaust gas cleaning and return of the fine material components to the vortex bed reached.

So that only those granules are removed from the fluidized bed, which have reached the desired grain size will be in a wide range Ren proposed that the granules over a or several sifters from the fluidized bed. These are in space-saving advantageous in the inflow floor of the fluidized bed appa used. Countercurrent Gravity classifier.

Are particularly suitable for use in the method according to the invention dere aqueous preparations of such valuable materials and material combinations ions from the field of wetting, washing and / or cleaning agents, caused by short-term exposure to water or water vapor in the Range of a product temperature of 100 to 120 ° C not or not we be significantly damaged. Are particularly suitable as a value fabric components Components of this type, which are included in the working area conditions the specified temperature range for at least one Period of about 5 s to 5 min. Survive harmless. Crucial is that the period of this temperature exposure in the invention essen procedure is kept so short that under the selected Ar working conditions substantial damage to the goods to be dried not yet occur. For example, hydroly Surfactant compounds at risk under these working conditions Ver  because periods of a few seconds to a few minutes largely survive unscathed, if certain, to the relevant specialist known framework conditions are observed. So it becomes possible that aqueous preparation in the drying process according to the invention gene water-soluble and / or insoluble organic and / or anor ganic materials from wetting agents, detergents and / or cleaning agents subject to drying, for example the following Substance classes can be assigned: Components with surfactant or emulsions door effect, inorganic and / or organic framework substances or Builder components, washing alkalis, adjusting agents or neutral salts, Fabric softeners, bleach activators, additives for improvement the dirt-carrying capacity of fleets such as graying inhibitors or abrasives.

In an important embodiment, the method according to the invention for drying mixtures of recyclable materials for building text detergents used. The aqueous application measure to be dried materials contain wash-active surfactants together with framework or builder substances, and if desired washing alkalis and / or Neutral salts. At least part of the is used here multi-component mixtures for binding and / or fixing residual water water, especially in the form of crystal water. Just like in Spray drying process of textile detergents is used in such Fabric mixtures usually do not contain the textile detergent in its All of the fluidized bed spray granulation exposed. The extreme temperature sensitivity of peroxide-containing bleaching components, such as perborate monohydrate or tetrahydrate and correspond other particularly temperature-sensitive components not to. As further examples are enzymes, fragrances, bleach tivators and other small components called. The teaching of Accordingly, the invention accordingly sees the manufacture of so-called called multi-component tower powder, which a large part of the  Components making up the finished detergent are combined in a mixture included, but later with liquid and / or solid white teren active ingredient components are applied or mixed. Be Known examples of such liquid components are in particular volatile non-surfactant components in the invention The process is no longer released into the environment via the exhaust gas are, the addition to the total detergent by after Sluggish spraying on an absorbent prepared according to the invention granules can be easily designed.

The following is general information on valuable materials for the direct or indirect use in the manufacture of Wetting agents, detergents and / or cleaning agents using the inventions working principles according to the invention, this compilation on heu te common components of textile detergents is shown.

For example, soaps made from natural or synthetic, preferably saturated, fatty acids can be used as anionic surfactants. Soap mixtures derived from natural fatty acids, for example coconut, palm kernel or tallow fatty acids, are particularly suitable. Preference is given to those which are composed of 50 to 100% of saturated C _12-18 fatty acid soaps and 0 to 50% of oleic acid soap.

Other suitable synthetic anionic surfactants are those of Type of sulfonates and sulfates. This can be particularly important Plant method according to the invention for corresponding compounds and / or of animal origin.

Suitable surfactants of the sulfonate type are alkylbenzenesulfonates (C _9-15 -alkyl), olefin sulfonates, ie mixtures of alkene and hydroxyalkane sulfonates, and sulfonates such as are obtained, for example, from C _12-18 monoolefins with a terminal or internal double bond by sulfonating with gaseous sulfur trioxide and subsequent alkaline or acid hydrolysis of the sulfonation products. Also suitable are the alkanesulfonates which are obtainable from C _12-18 alkanes by sulfochlorination or sulfoxidation and subsequent hydrolysis or neutralization or by bisulfite addition to olefins, and in particular the esters of alpha sulfo fatty acids (ester sulfonates), e.g. B. the alpha-sulfonated methyl ester of hydrogenated coconut, palm kernel or tallow fatty acids.

Important surfactant or emulsifier components in this context are also the so-called di-salts, which can be prepared by saponification of the aforementioned alpha-sulfonated fatty acid methyl esters or by direct sulfonation of, in particular, saturated fatty acids - in particular C _12-18 fatty acids.

Suitable surfactants of the sulfate type are the sulfuric acid monoesters from primary alcohols of natural and synthetic origin, ie from fatty alcohols, e.g. As coconut fatty alcohols, tallow fatty alcohols, oleyl alcohol, lauryl, myristyl, palmityl or stearyl alcohol, or the C _10-20 oxo alcohols, and those secondary alcohols of this chain length. The sulfuric acid monoesters of alcohols of natural and / or synthetic origin ethoxylated with in particular 1 to 6 mol of ethylene oxide are also suitable components. Examples of synthetic alcohols are compounds such as 2-methyl-branched C _9-11 alcohols with an average of 3.5 moles of ethylene oxide. Sulfated fatty acid monoglycerides are also suitable.

The anionic surfactants can be in the form of their sodium, potassium and Ammonium salts as well as soluble salts of organic bases.  

Addition products from 1 to 40 are nonionic surfactants. preferably 2 to 20 moles of ethylene oxide to 1 mole of an aliphatic Compound having essentially 10 to 20 carbon atoms from the Group of alcohols, carboxylic acids, fatty amines, carboxamides or Alkanesulfonamides can be used. The attachments are particularly important Products from 8 to 20 moles of ethylene oxide to primary alcohols, such as. B. on coconut or tallow fatty alcohols, on oleyl alcohol, on oxo alcohols or to secondary alcohols with 8 to 18, preferably 12 to 18 C- Atoms. In addition to the water-soluble nonionics, however, are also not or not completely water-soluble polyglycol ethers 2 to 7 ethylene glycol ether residues in the molecule of interest, esp especially when combined with water-soluble, non-ionic or anionic surfactants are used. In the method according to the invention The carryover tendency of such nonionic surfactants can be increased are taken into account that components of this type entirely or partially upon completion of the fluidized bed spray granulation the granules obtained are applied. In particular, it can also apply to nonionic surfactants that are liquid at room temperature.

In addition, alkyglycosides of the general formula RO- (G) _x can also be used as nonionic surfactants, in which R is a primary straight-chain or branched aliphatic radical having 8 to 22, preferably 12 to 18 C atoms, G is a symbol which stands for a glycose unit with 5 or 6 carbon atoms, and the degree of oligomerization x is between 1 and 10.

As an organic and inorganic framework or builder sub punches are weakly acidic, neutral or alkaline de Soluble and / or insoluble components to remove the calcium ions fall or bind complex. Suitable and in particular Ecologically harmless builder substances are fine crystalline synthetic zeolites of the kind already described. As further  Builder components, in particular together with the zeolites can be used, come in (co) polymeric polycarboxylates Consider, such as polyacrylates, polymethacrylates and copo in particular polymers of acrylic acid with maleic acid, preferably those with 50 up to 10% maleic acid. The molecular weight of the homopolymers is generally between 1,000 and 100,000, that of the copolymers between 2,000 and 200,000, preferably 50,000 to 120,000 for free acid. A particularly preferred acrylic acid-maleic acid Copolymer has a molecular weight of 50,000 to 100,000. Suitable, albeit less preferred, compounds of this class are copolymers of acrylic acid or methacrylic acid with vinyl ethers, such as vinyl methyl ether, in which the proportion of acid is at least 50% is. Also useful are polyacetal carboxylic acids, as in for example in US Pat. Nos. 41 44 226 and 41 46 495 are written, as well as polymeric acids, which by polymerization of Acrolein and subsequent disproportionation using alkalis are kept and from acrylic acid units and vinyl alcohol units or acrolein units are constructed.

Usable organic builders are, for example, be preferably polycarboxylic acids used in the form of their sodium salts, such as citric acid and nitrilotriacetate (NTA), if such Use for ecological reasons is not objectionable.

In cases where a phosphate content is tolerated, too Phosphates are used, in particular pentasodium triphosphate, optionally also pyrophosphates and orthophosphates contained in it act as a precipitant for lime salts.

Suitable inorganic, non-complexing salts are the bicarbonates, carbonates, borates or silicates of the alkalis - also referred to as "washing alkalis"; Of the alkali silicates, especially the sodium silicates with a Na ₂ O: SiO ₂ ratio of 1: 1 to 1: 3.5 can be used. From the remaining groups of conventional detergent components, components from the classes of graying inhibitors (dirt carriers), neutral salts and textile-softening auxiliaries are particularly suitable for use in the process according to the invention.

Suitable graying inhibitors are, for example, carboxymethyl cellulose, methyl cellulose, methyl hydroxyethyl cellulose and their Mixtures. As a typical example of a suitable representative of the Neutral salts include the sodium sulfate already mentioned. Ge Suitable plasticizers are, for example, swellable layered silicates of the type of corresponding montmorillonites, for example bentonite.

High-temperature-sensitive common mixture components of washing and cleaning agents, such as bleaches based on per-compound genes, enzymes from the class proteases, lipases and amylases or Bak strains or mushrooms, stabilizers, perfumes, temperature sensitive Liche dyes and the like, as already stated expediently mixed with the previously obtained granulate.

The following are examples and test results of the invention according to the method described in more detail.

Fig. 1 shows schematically the pilot plant. It consisted mainly of a vortex chamber 1 with a two-part, separately inflatable slot floor 2 , a rotary valve 3 for product discharge and an integrated in the vortex chamber 1 tube bundle heat exchanger 4 , which was installed above the slot floor 2 . A conveyor screw 5 with feed hopper 6 was used to return the ground oversize. The material to be dried, the slurry, was pumped from a heated template via line 7 to a single-component nozzle and sprayed into the fluidized bed.

A blower 8 promotes water vapor through a heat exchanger 9 provided for reheating (overheating) into the swirl chamber 1. A flow measuring and control device 10 was connected between the blower 8 and the heat exchanger 9 . The escaping steam was cleaned of dust in a cyclone 11 and returned via a further fan 12 . The excess vapors were removed at 13 . To start the experiment, a connection 14 to the circuit line for steam was provided.

At the beginning of the experiment, so-called "tower powder" was used as bed material submitted. This was in with conventional hot air drying a production spray tower (bulk density 550 g / l, residual moisture approx. 12%). The tower powder contained about 16% by weight Surfactants, approx. 15% by weight soda and 28% zeolite NaA, approx. 2% water glass, Sokalan (R) and common small components.

After fluidizing the fluidized material with hot air, the Single-substance nozzle (0.7 mm hole) sprayed into the detergent slurry (approx. 30 kg / h at 6 bar spray pressure). Its solids content contained the components specified above.

The initial moisture of the slurry was 50%. The moist exhaust air was partly discharged, but for the most part it was circulated, the circulating air flow in the heat exchanger 9 before the fluidized bed being heated again. The extracted air flow was replaced by fresh air. The temperature of the air was about 145 ° C at the entry into the fluidized bed and about 90 ° C at the exit.

Part of the granules produced was discharged from the fluidized bed via the rotary feeder 3 , ground and fed back via the screw conveyor 5 as granulation nuclei of the fluidized bed.

The residence time of the product in the fluidized bed was about 20 minutes.

After no increase in bulk density was found for several hours, the switch was made to drying with superheated steam. The steam, like the air before, was circulated. The steam overheated again by the heat exchanger 9 in front of the fluidized bed and the tube bundle heat exchanger 4 arranged therein. The steam inlet temperature was on average 150 ° C, the steam temperature at the outlet of the fluidized bed 105 ° C. The slurry throughput was 30 kg / h. At the beginning of steam drying, the granulate produced in the preliminary experiments with air drying was used as the bedding. The residence time of the product in the fluidized bed was about 20 minutes.

The test results are shown in Tables 1 and 2.

Table 1 shows the bulk densities of three from the fluidized bed samples taken:

Sample 3 at the end of the experiments with air drying
Sample 6 after drying with steam and simple bed exchange
Sample 7 after drying with steam and double bed exchange.

Table 1

A significant increase in bulk density of 687 can be observed mg / l of sample 3 over 782 mg / l of sample 6 to 820 mg / l of sample 7. The residual moisture in all cases was approx. 5% (measured with infra red drying at 135 ° C and 7 min).

The sieve analyzes carried out (Table 2) show a shift to larger particles when drying with steam.

Images with a light microscope show the steam-dried particles ( Fig. 2, 25 times magnification, sample 7) a much smoother and more uniform surface compared to the air-dried ( Fig. 3, 25 times magnification, sample 3). Images of the grain interior show fewer and smaller pores in the steam-dried granulate.

Caking on the heat exchanger 4 in the fluidized bed and product damage through direct contact with the heat exchanger tubes were not observed.

Table 2

Sieve analysis

Reference list

1 swirl chamber
2 slotted floor (inflow floor)
3 rotary valve
4 heat exchangers
5 screw conveyor
6 feed hoppers
7 line
8 blowers
9 heat exchangers
10 flow, measuring and control device
11 cyclone
12 fan
13 excess vapors
14 connection

Claims (25)

1. Process for the in particular continuous production of free-flowing and free-flowing granules of valuable substances or mixtures of substances which are suitable as wetting agents, detergents and / or cleaning agents and / or for use in such agents, from their aqueous solutions and / or suspensions Fluidized bed spray granulation in a hot fluidizing gas in the range of normal pressure, characterized in that one works with superheated steam as the fluidizing gas, thereby removing the granulate from the granulator before it is endangered by thermal action and the storage-stable pourability and free-flowing properties of the partially dried-up material Good, if necessary, by adding limited amounts of water to qualified mixture components and / or after-treatment ensures that one works in a closed system with a steam cycle flow from which the evaporated water portion of the feed is withdrawn as a partial flow and supplies the heat energy again. 2. The method according to claim 1, characterized, that one integrated the superheated steam in the fluidized bed as well also supplies heat energy via external heat exchangers. 3. The method according to claim 1, characterized, that one is particularly sensitive thermally when drying Valuable materials or mixtures of them from superheated steam only supplies heat energy via external heat exchangers, whereby one shorter dwell times than with heat integrated in the fluidized bed exchangers.   4. The method according to any one of claims 1 to 3, characterized, that one draws the partial flow extracted from the water vapor cycle cleaned of carried parts of the input material and as Process steam used elsewhere. 5. The method according to any one of claims 1 to 4, characterized, that you have at least a portion of the water vapor cycle condensed partial flow condensed and together with the valuable materials contained therein, if necessary after previous ones Concentration, for the preparation of the aqueous to be dried Uses solutions and / or suspensions. 6. The method according to any one of claims 1 to 5, characterized, that with internal pressures of the steam-filled system in the area of normal pressure, but preferably with such raised Pressing works, so that air intakes, for example damage put in the system to be prevented, being system inside pressures below about 50 mbar are preferred. 7. The method according to any one of claims 1 to 6, characterized, that one is incomplete to at least partially bind the im dig dried product contained residual water auxiliaries uses, so that the storage-stable bulk and pourability of the dry goods is ensured, and these auxiliaries, too at least in part, the aqueous solutions or suspensions added before the fluidized bed spray granulation.   8. The method according to claim 7, characterized, that components as auxiliary substances for binding the residual water the wetting agent, detergent or cleaning agent, in particular builder, Used alkalis and / or adjusting agents. 9. The method according to any one of claims 1 to 8, characterized, that the drying with the superheated steam in the Fluidized bed with residual water content in the range of about 1 to 20% by weight, in particular in the range from about 5 to 15% by weight breaks and preferably the content of free, not as Water bound to water of crystallization to values of at most about 10 Wt .-%, each based on the weight of the vortex discharged good, limited. 10. The method according to any one of claims 1 to 9, wherein the heat is finally introduced via the vapor phase, characterized, that you have water vapor at an inlet temperature of about 270 to 350 ° C as fluidizing gas for the fluidized bed. 11. The method according to any one of claims 1 to 9, wherein the heat additionally via heat exchangers integrated in the fluidized bed brings in, characterized, that the inlet temperature of the water vapor at 150 to 180 ° C. lies. 12. The method according to claim 16, characterized, that with at least partial recovery of the condensation  heat of the discharged steam component and preferably with it Return of the discharged shares in the primary cycle practically free of exhaust gas and loaded waste water. 13. The method according to any one of claims 1 to 12, characterized, that the residual moisture content of the granules obtained in one homogenized at least one-step after-treatment step. 14. The method according to claim 13, characterized, that the residual moisture content in another fluidized bed homogenized with air as the fluidizing gas. 15. The method according to any one of claims 1 to 10, characterized, that the granules still containing residual water are undervalued conditions gentle to the material agglomerate and dry or aftertreated. 16. The method according to any one of claims 1 to 11, characterized, that the fine escaping from the fluidized bed with the exhaust gas separates well and as germs for the granulate formation in special internally with the help of a arranged above the fluidized bed dust filter into the fluidized bed. 17. The method according to claim 16, characterized, that one integrated the exhaust gas in the head of the granulator and cleans cloth filters arranged above the fluidized bed.   18. The method according to any one of claims 1 to 17, characterized, that the granules over one or more, especially in Inflow floor of the fluidized bed apparatus used sifters, especially countercurrent gravity classifier from the vortex layer wears out. 19. The method according to any one of claims 1 to 18, characterized, that aqueous preparations of such valuable materials or valuable material uses combinations that are caused by short-term exposure to Water and steam in the temperature range from 100 to 120 ° C not be damaged and at least this temperature range for a period of 5 s to 5 min. in the used accessory Survive the form without damage. 20. The method according to any one of claims 1 to 19, characterized, that aqueous preparations are water-soluble and / or insoluble organic and / or inorganic materials from wetting, Detergents and / or cleaning agents, such as components with tenside or emulsifier effect, inorganic and / or organic framework substances or builder components, washing alkalis, adjusting agents or neutral salts, fabric softeners, bleach activators, auxiliaries substances to improve dirt-bearing capacity such as graying Inhibitors and abrasives subject to the process. 21. The method according to any one of claims 1 to 20, characterized, that organic components selected as valuable materials or inorganic in nature from the classes of surfactants or emuls gators or the builder or builder, in particular  the field of valuable materials for textile detergents, as free-flowing dry goods can be obtained. 22. The method according to any one of claims 1 to 21, characterized, that mixtures of valuable materials for the construction of textile detergents be dried, the surfactants together with framework or Builder substances and, if desired, washing alkalis and / or Contain neutral salts, with at least part of the more mixtures of substances for binding and / or fixing residual water is capable. 23. The method according to any one of claims 1 to 22 for the production of free-flowing surfactant solids, especially anionic surfactants based on natural substances, especially when mixed with soluble Chen inorganic salts to ensure the pourability and / or the bulk density are present. 24. The method according to any one of claims 1 to 22 for the production of dried silicate-based materials, which are particularly useful in Textile detergents can be used and correspond appropriate swellable and / or non-swellable representatives such as Layered silicates and / or zeolite compounds, in particular Zeo lith NaA in detergent quality. 25. The method according to any one of claims 1 to 22 for the production of Textile detergent tower powders, to which temperature-sensitive and / or steam-volatile components to build the finished Textile detergents can be added.