HU204207B - Method for continuous producing granules - Google Patents

Abstract

Granular materials having a narrow particle size distribution can be produced according to a novel process by a) spouting the product to be granulated in liquid form into a fluidised bed, b) precipitating the proportions of fines escaping with the off-gas from the fluidised bed and returning them as nuclei for the formation of granules into the fluidised bed, c) influencing the granulation process in the fluidised bed, by adjusting the classifying-gas stream only, in such a manner that granules are produced with a size defined by the classifying-gas stream, and d) removing the finished granules only, via one or more countercurrent/gravity classifiers set in the gas distributor plate of the fluidised-bed apparatus and e) subjecting the granular materials thus obtained to a thermal secondary treatment if required. The novel apparatus for producing granular materials according to the invention essentially comprises a fluidised-bed granulator, - which comprises devices for atomising the product fed in in sprayable form, - which further comprises a system suitable for returning proportions of fines escaping from the fluidised bed and - directly attached to whose gas distributor plate are one or more countercurrent/gravity classifiers. The granular materials which can be produced according to the process of the invention are likewise novel.

Description

The present invention relates to a process for the continuous production of granules.

A number of processes are already known for producing granular material by vortex bedding (see Chem. Ing. Techn. 45, 736-739, p. 5 [1973], U.S. Patent Nos. 2231445 and 2555,917, and European Patent Specification 0 087 039). publication document). In these said processes, which are continuous processes, the ready-to-use granulate is obtained in a single step without further post-drying. In essence, three different methods can be distinguished in this context, but each is based on the same granulation process. Thus, in each case, the material to be granulated is sprayed into a fluid bed in a state suitable for atomization, i.e. as a melt, suspension or solution. The sprayed liquid first moisturizes the surface of the solid particles in the fluidized bed and then solidifies as it dries and cools.

In this way, the particles grow shell-like, that is, the larger they stay in the crib. Therefore, the size of the granulate is largely dependent on the bed capacity, i.e. volume.

The growth of particles in the crib begins with crystal sprouts, which are either formed by non-collapsing, self-consolidating droplets in the crib itself or are formed by crumbling of the solid particles already present or introduced externally into the crib. The internal crystalline germ formation that occurs in the crib itself is influenced by the loading of the crib so that the number of non-colliding droplets decreases with increasing bed loading. On the other hand, the number of crystal germs produced by churning is increasing. 35

The process required to produce granules at a given particle size is determined by the sum of the number of crystal germs and the growth of the granules in a fluidized bed granulation. The granulation process can thus be influenced in such a way. so e.g. the available crystal germ number 40 can be supplemented by adding crystal germs externally.

Steady granulation conditions are provided if the bed load can be kept constant. In the stationary state, the amount of solids introduced into the fluidized bed should be equal to the weight of the finished granules leaving the bed. In addition to the mass balance, however, the particle balance must also be balanced. This means that all the granules removed from the cot must be replaced with new germs. The known processes employ a constant granulation process. The methods differ in the way in which this constancy is achieved.

In the processes described in U.S. Pat. Federal Patent Publication No. 0 087 039; EP Publication 55 discloses only internally-formed fluidized bed control, based on the principle of filling level, operates an outlet and thereby ensures consistency between granule release and feed 60 The granular material exiting the granulator is classified and the resulting fine grit back to the grater. However, since the level control does not apply to sequentially connected equipment parts at different throughput capacities, only a classification stage can be used whose particle size passage through the outlet, irrespective of the separation sharpness, matches the corresponding throughput power. Accordingly, a second fluidized bed is used as a screening section in these processes. The latter classifies the particles only very imprecisely. Therefore, this method is not suitable for producing a granular material with a narrow particle size distribution.

No. 2,263,968. The pelletizing process described in the German patent application is essentially the same. Here, however, a sharp separation screen is used as a screening section instead of a second vortex bed. The necessary synchronization of the throughput of the screening section with the outlet organ is accomplished by retaining some of the particles but retaining them and then returning them to the fluidized bed. This additional introduction of crystal germ into the fluidized bed should be compensated by reducing crystal germ formation. The reduction of crystalline germ formation in the fluidized bed is achieved by operating the sequencer with a large bedding. However, a prerequisite for this operation is a wear-resistant granulate.

The process results in a granular material having a narrow particle size distribution. However, it has the disadvantage that it requires extremely large equipment. In addition, this process does not allow granulation of wet or dust explosive materials from the solvent, since the auxiliary equipment required for the fluidized bed granulator cannot be neutralized or explosion-proof.

No. 2,555,917. In the third version, described in the publication of the Federal Government of the Federal Republic of Germany, it is a counter-current, gravity-force classifier, acting as a discharge organ! employed. This grinder combines the role of grading section and delivery unit With this machine, only granules that reach the desired particle size are removed from the bed. The fluctuation in the number of granules applied always directly affects the bedding. If, for example, the bed load increases, then the granules formed are too small. The growth of the granules must therefore be promoted and the introduction of the crystal germ, which occurs from the outside, must be suppressed. In order to effectively influence the regulation of the crystal germs available for the granulation process, the formation of the inner crystal germ should be minimized, which can be achieved with a large bedding for abrasion-resistant granules.

Finally, with this known solution, granules with a narrow particle size distribution can be obtained. However, it is disadvantageous that the control of the crystal germ feed is very complicated. In addition, the process of switching from a specific middle particle size to another middle particle size is only complicated by patch2.

HU 204207 Β can be realized by living work based on talent. The same applies to all the procedures described above.

Therefore, a novel process for the continuous production of narrow particle size granules has been developed, which consists of spraying the material to be granulated into a fluid bed, separating the fine powder leaving the exhaust gases and recirculating the gas stream to the fluid bed to form granules. in the fluidized bed, the granules are formed by the size of the screening gas stream, and the finished granulate is taken only through one or more counterflow classifiers mounted on the fluid bed bottom of the fluidized bed, and the resulting granulate is optionally subjected to thermal curing.

Figure 9 illustrates a possible apparatus for the continuous production of a narrow particle size granule comprising essentially a fluidized bed granulator comprising apparatus for atomizing the material fed in a sprayable form and a system for recirculating the fine stream escaping from the bed one or more counter-current gravity classifiers are located on the bottom.

Finally, a novel granulate is prepared according to the process of the present invention, characterized in that the granular product contains from 1 to 100% by weight of active ingredient, 0 to 99% by weight of inert filler, 0 to 40% by weight of dispersant and / or binder and optionally filler. , average particle size 0.1-3 mm, dispersible or soluble in water and other solvents.

The process according to the invention differs from all previously known processes in that the granulate formation process automatically adjusts to the size of the granules discharged by the introduction of the screening gas during the interaction of granule growth and crystal germ formation.

The process according to the invention has many advantages over known methods. so e.g. in any case, granules of the desired particle size can be produced, but the particle diameter, i.e., the particle spectrum, remains very narrow. In addition, the particle size can be varied from case to case by simple introduction of the shielding gas without the need to change the equipment. Moreover, the particle size can be changed during operation.

The great advantage is that only granular products are formed, i.e. granules of the desired size. Thus, no material loss occurs because too small particles remain in the fluidized bed until they reach the desired size. Too large particles also do not form because the particles are carried out of the crib by constant grading. Therefore, the milling and sieving processes are completely absent. A further advantage is that no foreign crystal germs need to be introduced to influence the process. It is also preferred that the liquid product to be sprayed into the fluidised bed in the process of the present invention may have a very high solids content. The resulting granules are uniform in shape, homogeneous and, despite their high strength, can be spontaneously dispersed or soluble in water or other solvents. Since the process does not impose requirements on the wear resistance of the granules, low-binder granules can also be produced, which advantageously affects its dispersion property.

Finally, the process according to the invention can also process wet and dust explosive products from a solvent, since the equipment required for this can be neutralized and explosion-proof.

In the process of the present invention, the product to be granulated is sprayed into the fluid bed in liquid form. The liquid may be a melt, solution or suspension (slurry).

The liquid to be sprayed may contain one or more active components Substances which are solid or liquid at room temperature may be used as the active component. The prerequisite for the use of the liquid active ingredients is that they are applied to solid carriers prior to the granulation. The active components may be water-soluble or water-insoluble. They must be stable to hydrolysis so that during the process according to the invention and when the granules so obtained are used in the presence of water, they are not subject to any significant degradation.

Examples of active ingredients are agrochemicals, household or hygiene pest control agents, pharmacologically active substances, nutrients, sweet products, dyes and organic or inorganic chemicals.

Agrochemicals, as used herein, are understood to be the compounds commonly used in plant protection. Preferred are insecticidal, acaricidal, nematicidal, fungicidal and herbicidal agents, as well as growth regulators and nutrients. Examples of such active substances include: 0.0-diethyl-1- (4-nitrophenyl) -thionophosphoric ester, 0.0-dimethyl-O- (4-nitrophenyl) -thionophosphoric acid. ester, 0-ethyl-0- (4-methylthio) phenyl-S-propyl dithiophosphate, (O-O-diethylthionophosphoryl) -α-oxominophenylacetic acid nitrile,

2-isopropoxyphenyl-N-methylcarbanate, propionic acid 3,4-dichloroanilide,

3- (3,4-dichlorophenyl) -1,1-dimethylurea,

3- (4-chlorophenyl) -1,1-dimethyl-kaibamid,

N- (2-benzothiazolyl) -NN'-dimethylurea,

3- (3-chloro-4-methylphenyl) -l, l-dimethylurea,

3- (4-isopropylphenyl) -1,1-dimethylurea,

4-amido-6- (1,1-dimethylethyl) -3-methylthio-1,2,4-triazin-5 (4H) -one,

4-amino-6- (1,1-dimethylethyl) -3-ethylthio-1,2,4-triazin-5 (4H) -one,

1-amino-6-ethylthio-3- (2,2-dimethylpropyl) -1,3,5-triazine-2,4- (1H, 3H) -dione,

4-amino-3-methyl-6-phenyl-l, 2,4-triazin - 5 (4H) -one,

2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine,

EN 204207 α2- [4- (3,5-Dichloropyridyl-2-oxy) -phenoxy] -propionic acid (trimethylsulfyl) -methyl ester R-enanthioine, a2- [4- (3,5-dichloropyridyl-2-oxy) R-enantiomer of -phenoxy] -propionic acid (2-benzyloxy) ethyl ester,

2.4-dichlorophenoxyacetic acid, 2- (2,4-dichlorophenoxy) propionic acid,

4-Chloro-2-methyl-phenoxy-acetic acid, 2- (2-methyl-3-chloro-phenoxy) -propionic acid,

3.5-diiodo-4-hydroxybenzonitrile,

3.5-dibromo-4-hydroxybenzonitrile such as diphenyl ether and phenylpyridazines such as pyridate;

2,3-dihydro-2,2-dimethyl-7-benzofuranyl-methyl-carbamate,

3,5-Dimethyl-4-methyl-thiophenyl-N-methyl-carbamate, 0,0-diethyl-O- (3-chloro-4-methyl-7-coumarinyl) -thiophosphate ^N '- (4-methylphenyl) sulfamide, l- (4-Chloro-phenoxy) -3,3-dimethyl-l- (l, 2,4-triazol-l-yl) butan-2-one, l - (4-chlorophenoxy) -3,3-dimethyl-1- (1,2,4-triazol-1-yl) butan-2-ol,

1-cyclohexyl-4,4-dimethyl-3-hydroxy-2- (1,2,4-triazolyl) pent-1-ene,

2- (2-furyl) -benzimidazole,

5-amino-1-bis (dimethylamido) phosphoryl-3-phenyl-1,2,4-triazole,

4-hydroxy-3- (1,2,3,4-tetrahydro-1-naphthyl) coumarin,

5- [1,2-Bis (ethoxycarbonyl) ethyl] -0,0-dimethyldithiophosphoric ester,

0,0-dimethyl-0 '(4-metiImerkapto-3-methylphenyl) -tiofoszforsavészter,

O-Ethyl-O- (2-isopropoxycarbonylphenyl) -N-isopropylthionophosphoric ester and (S) -α-thieno-3-phenoxybenzyl (1R) -cis-3- (2,2-dibromovinyl) -2,2-dimethylcyclopropane-carboxylate in.

Active substances used in the household and health fields are those commonly used for such purposes. Examples include:

2-isopropoxyphenyl-N-methylcarbamate,

0.0-diethyl-O- (4-nitrophenyl) -thiophosphoric acid ester, 0.0-dimethyl-O- (4-nitrophenyl) -thiophosphoric acid ester,

S- [l, 2-bis (ethoxycarbonyl) ethyl] -0,0-dimethyl-dithiophosphoric acid ester,

0,0-dimethyl-0- (3-methyl-4-phenyl-Nitto) -thione-phosphoric acid,

0,0-Dimethyl-O- (4-methylthio-3-methylphenyl) -thiophosphonic acid ester, (cyclohex-1-en-1,2-dicarboximidomethyl) -2,2-dimethyl-3- (2-methylpropenyl) ) cyclopropane-carboxylate.

By "pharmaceutically active substances" is meant herein active ingredients in both human and veterinary medicine. Exemplary veterinary agents include 2,2-dimethyl-3- [4 - [(p-chlorophenyl) p-chloroformyl] cyclopropanecarboxylic acid alpha-cyano-3-phenoxy-4-fluorobenzyl ester. An example of an active ingredient in human medicine is acetylsalicylic acid.

Both human and animal nutrition materials can be used as nutrients. Examples include citric acid, vitamins, coffee powder, tea powder and cocoa powder. The sweetening agent may be, for example, sodium cyclamate or saccharin

For dyes, coloring dispersions or materials suitable for use as dyes and / or coating dyes, such as water-soluble dyes such as cationic, anionic and reactive dyes, and water-insoluble dyes such as bath dyes, polyester dyes and pigments may be used. Examples include indathrene dyes, cerofix dyes, astrazone, triarylamine, triarylmethane, methine, anthraquinone, indigo, sulfur, azo and pigment dyes.

Suitable organic or inorganic chemicals are those which are preferably used in the synthesis of aqueous dispersions. Alternatively, aqueous zeolite dispersion catheters (such as those described in Ullmann Volume 4, Volume 17, under "Molecular Filters") may be used. In addition, suspensions of inorganic oxides suitable for the preparation of catalysts or catalyst supports may be used. Examples include alumina and silicon oxide.

In carrying out the process of the present invention, the liquid ingredients to be fluidized into the vortex layer may include inert fillers, dispersants, binders and / or additives, such as preservatives and dyes, in addition to the active ingredients and the liquid diluent optionally present.

Suitable fillers include any of the water-dispersible or water-soluble granules or fillers and carriers used in oil-soluble granules. Inorganic salts such as alkali metal, magnesium and ammonium chloride and sulfate, such as magnesium sulfate, potassium sulfate, sodium sulfate, potassium chloride, ammonium sulfate, lithium sulfate and ammonium chloride, and oxides such as magnesium oxide; nitrates, carbonates, bicarbonates, silicates, bentonite attapulgite and sepiolite, and urea and urea derivatives of graphite such as bexamethylene tetramine and casein, and finally carbohydrates such as starch, sugar, alginates and derivatives thereof, cereal grains such as wheat and rice; , methylcellulose and hydroxypropylmethylcellulose, water-soluble polymers such as polyvinyl alcohol and polyvinylpyrrolidone,

Preferred dispersants are the condensation products of aromatic sulfonic acids with formaldehyde, such as the sulfonated ditolylether and the condensation product of formaldehyde, and the salts of lignin sulfonic acid such as lithium, sodium, potassium, potassium, ; methyl cellulose, polyoxyethylene fatty acid ester, polyoxyethylene fatty alcohol ethers such as alkylaryl polyglycol ether, and finally alkyl sulfonates and protein dibrolysates.

The dissolved dispersant itself can be rapidly reconstituted to form a granulate.

Further, a slurry of anionic detergents can be processed

EN 204207 esetben optionally in the presence of nonionic surfactants, builder, optical brighteners, plasticizers and / or fragrances.

The binder may be any water-dispersible or soluble granules or any of the usual binders for oil-dispersible or soluble granules. We prefer solutions, emulsions or latexes of natural or synthetic materials such as methylcellulose, dextrin, sugar, starch, alginates, glycols, polyvinylpyrrolidone, lignin sulfonate, gum arabic, polyvinyl alcohol and polyvinyl acetate with methanol, methanol, mixtures. In some cases, water glass and silica sol may be used.

Examples of preservatives that may be present in the liquid product to be sprayed include 2-hydroxybiphenyl, sorbic acid, p-hydroxybenzaldehyde, methyl p-hydroxybenzoic acid, benzaldehyde, benzoic acid and propyl p-hydroxybenzoic acid. Examples of coloring agents which may be used as additives include inorganic pigments such as iron oxide, titanium oxide and berries, or organic dyes such as alizarin, azo-metal phthalocyanine.

When the process according to the invention comprises a solid active ingredient or a binder at room temperature, these materials must be incorporated into the vortex layer as a melt, solution or suspension. For the preparation of solutions or suspensions, the usual inert organic solvents and water may be used. Preferred organic solvents are: alcohols such as ethanol and glycol; aliphatic and aromatic, optionally halogenated hydrocarbons such as ligroin, hexane, gasoline, benzene, toluene, xylene, dichloromethane, carbon tetrachloride and chlorobenzene; ethers such as dioxane, tetrahydrofuran, anisole; ketones such as acetone, methyl ethyl ketone and cyclohexanone; highly polar solvents such as hexamethylphosphoric triamide, acetonitrile, dimethylformamide and dimethylsulfoxide. Water is particularly preferred.

In the case of the liquid materials which can be sprayed into the fluidized bed in accordance with the process of the invention, the solids content may vary over a larger range. Generally, the solids content of the suspension is between 5 and 75% by weight, preferably between 10 and 65% by weight.

Liquid materials to be sprayed are prepared by conventional methods by mixing the ingredients in the desired proportions and optionally heating the mixture.

The granulation may be carried out in air or in an inert gas such as. nitrogen. According to the process according to the invention, the granulation can be started in a fluidized bed apparatus which already has an initial granulate. However, it is also possible to start the granulation in an empty machine. In this case, the fluidized bed granulation according to the invention starts as a spray drying. Gradual filling of the fluidized bed will then result in a bed filling in which the granules reach and exit the desired size. If materials are used which tend to form a coating on the wall of the apparatus, it is preferable to use starting granules at the start of the process. In fact, this measure will largely eliminate spraying on the walls.

In the process of the invention, the liquid material to be granulated is introduced into the fluidized bed by means of spray nozzles. It is highly advantageous to use dual nozzles. The spray gas may be any gas which is inert to the working conditions. Preferably, air or an inert gas, such as nitrogen. The amount of gas used for atomization can be varied within wide limits, generally depending on the size of the equipment and the type and amount of material to be atomized.

Generally, the following amounts of atomizing gas will be used with respect to the materials employed: 0.1 kg gas / kg feed material - 10 kg gas / kg feed material, preferably 0.5-5 kg gas / kg feed material. The temperature of the atomising gas can also be varied within a wide range: generally, a temperature of from 0 to 250 ° C is employed, preferably 20200 ° C.

With the exhaust gas, the fine powder escaping from the fluid bed is separated and returned to the fluid bed for crystallization as a germ. Meanwhile, it is possible to recycle the fine grind internally or externally. During the internal recirculation of the fine powder, the powder is separated by a filter placed directly on the fluidized bed and returned to the fluidized bed by means of cleaning pulses. In the case of external recirculation, the powder is separated from the exhaust gas outside the granulator. Any conventional apparatus suitable for this purpose can be used to separate the escaped fine ground. In a very preferred embodiment, the fine grind is separated by cyclone or dust filter. The separated fine powder is returned to the spray bed spray stage. The recirculation is preferably pneumatic. The propellant gas may be any conventional gas which is inert to the working conditions. Preferred air and inert gas, e.g. nitrogen. The amount of propellant gas can be varied over a wide range, generally depending on the size of the equipment and the amount of fine powder escaped. Generally, 0.01 kg gas to 2 kg gas / kg fine ground propellant are used. Preferably, the amount of gas is 0.1 to 1 kg of gas / kg of fine powder. The temperature of the propellant stream can also be varied within a wide range, generally ranging from 20 ° C to 350 ° C, preferably 30 ° C to 300 ° C.

In the fluidized bed, the granulation process in the fluidized bed is maintained solely by the amount of liquid material to be granulated and the strength of the screening gas stream. No additional crystal germs are introduced externally Any conventional gas which is inert to the working conditions, preferably air or e.g. application of nitrogen. The amount of shale gas can be varied within wide limits, depending on the size of the equipment, the amount of pellets to be discharged and

EN 204207 Β depends on the size of the chuck. Generally, gas amounts of 0.2 kg gas / kg granules and 5 kg gas / kg granules are used. Preferably, the amount of screening gas is 0.4 to 2 kg gas / kg granulate. The temperature of the shielding gas can also be varied within wide limits, the temperature 5 generally being between 20 ° C and 350 ° C, preferably between 30 ° C and 300 ° C

The rate of screening gas depends on the grain size and density of the granules to be discharged. Generally, a speed of 0.515 m / sec, preferably 1-5 m / sec, is used.

In the process of the invention, the finished particulate material is delivered with a desire multi-counter gravity classifier. As a Hyen delivery system, any conventional grading system 15 can be used which operates on the above principle. If an extremely tight particle size distribution is required, a zigzag classifier as a special delivery device! employed.

In order to keep the amount of screening gas energetically as low as possible 20, a zigzag profile, i.e. a zigzag classifier, is used in the practice of the invention. wherein the length of the columns and thereby the screening cross-section are adjusted by means of combs interconnected with each other, adapted to the zigzag profile and slidable perpendicular to the screening axis. In a preferred embodiment, the ribs are provided with an actuator which is connected to a regulator and subsequently regulates the screening gas flow so that the flow velocity 30 in the screener remains constant despite the variable cross-section.

The process of the invention is generally carried out under atmospheric pressure. However, it is also possible to work with greater or lesser pressure. However, the countercurrent, gravity-force classifier 35 typically operates at atmospheric pressure at the output end. To achieve this, a fan, a throttle, or the like 40 is inserted between the exhaust air supply fan and the outlet of the screen, which adjusts the pressure to the ambient pressure at each outlet of the screen. If non-atmospheric pressure prevails at the outlet end of the classifier, sluices shall be provided to maintain the desired pressure.

The drawings illustrate an exemplary embodiment of an apparatus for carrying out the process of the invention.

Figure 1 is a graph showing the interaction between granule growth and crystalline germ formation, without consideration of wear.

Figure 2 is a graph showing the interaction between granule growth and crystal germ formation with respect to wear.

Figure 3 is a schematic representation of the apparatus with internal fine ground recirculation.

Figure 4 is a perspective view of a zigzag classifier at the outlet end of a fluid bed apparatus.

Figure 5 shows a cross section of a zigzag classifier.

Fig. 6 shows an adjusting device used for the zigzag classifier to adjust the outlet cross section of the zigzag.

7 is a graph showing the particle distribution obtained at the outlet end of the classifier. in the granules obtained by the solutions described in Examples 1 to 4.

Figure 8 is a cross-sectional view of the double filament.

Figure 9 is a schematic representation of the apparatus with an external fine ground recirculation.

The diagram in Figure 1 depicts the size and number of granule particles obtained as a result of the production of a fully abrasion resistant material as a function of the fluidity of the fluid bed.

The droplets formed by the nozzles partially collide with the particles circulating in the fluidized bed and thereby increase them. Non-colliding droplets solidify. They harden when it is a melt, dry out as a suspension and crystallize in small portions when it is a solution. These are separated from the exhaust gas and recycled to the vortex section of the vortex bed. They thus become new crystal germs, which can be adhered to by additional particles. With increasing bedding, particle growth improves at the expense of crystal germ formation. The size of the granules deposited in the stationary state is directly dependent on the number of crystalline germs formed, because the same number of finished granules as the number of crystal germs has to be applied. Depending on the number of finished granules, the dry weight fed should be distributed. Thus, the size of the granules is predetermined. For the sake of simplicity, the term granule size here refers to the weight of a granule core.

With a large crystal germ number and a suitable small bedding, many small granules can be produced as

Figure 1 shows the upper curve; while large bedding otherwise produces less large granules under the same conditions. If the nominal size of the finished granules is determined by adjusting the material to be graded, then, in accordance with the aforementioned relationships shown in Figure 1, a bedding is provided which carries the corresponding crystal germ number. This bedding automatically adjusts without any outside influence.

In this approach, an effect that plays a role in crystal germ formation, namely acupuncture, has been deliberately neglected. Due to wear, which depends heavily on the material, the conditions become a little more complicated.

) Unlike the primary crystal germs considered so far, the secondary crystal germs produced by wear grow with increasing bed load as

Figure 2. Primary and secondary crystal germs together provide all available crystal germs. In addition, the total crystal germ count goes through a minimum. Conversely, the maximum granule size should not be exceeded. In addition, there are two different bedding types for a given granule size. This requires that both operating points ¹ be checked for stability.

HU 204207 Β

A condition is known to be stable only when the reactions to the disturbances are such that these disturbances can be reversed. The disturbance may be, for example, if the bed occupancy is increased at the left operating point. The reaction to this disturbance is that the granule increases and, at the output of the classifier, the granule output also increases. The bedding is thus reduced again. The same reaction occurs if the interference occurs in the other direction. The operating point is thus stable.

The test gives a different result at the right operating point. Here the consequence of a larger bed filling is a smaller granule. Fewer granules can exit the classifier output. The bed load increases and thus the overall condition of the unit moves away from the operating point. Even if the disorder happens in the other direction, we get the result. The operating point is thus unstable.

The maximum of the curve thus determines the operating range of the self-regulating procedure. The pelleting process is stable only on the left and can therefore only be applied there.

Whether and at what point maximum is formed depends on the process of crystalline germination, which is primarily influenced by the substance itself. The main properties of the primary crystal germ formation are the viscosity of the feed material and the surface tension. The number of primary crystal germs can be influenced by the fineness of the atomization. In addition, the rate of solidification, which is influenced by the temperature of the fluidizing gas.

For secondary crystal germs, the binding effect of adherent solids is essential. Particle size, flow rate and bed time also play an important role.

The process of the present invention may be carried out in a fluidized bed apparatus such as that illustrated schematically in Figure 3, where internal fine ground recirculation is used.

This apparatus consists of a vertically erected container 1 with a perforated flow bottom 2 at its lower end and an exhaust gas filter located at its upper end. The exhaust gas generated is extracted by the fan 4. Gas is injected through the perforated flow bottom 2 so that a fluidized bed is formed in the container 1 above.

Preferably, the process of the present invention utilizes a fluidized bed granulator consisting of a two-piece, preferably cylindrical vessel. The lower part of this is subjected to a granulation process The upper part, preferably expanding to a double diameter of the lower part, serves to pre-select mid-size particles from the exhaust gas and to solidify the spray droplets which have not encountered any particles in the fluidised bed. .

The fine powder or powder can be separated from the exhaust gas inside or outside the fluidized bed granulator. The internal separation is preferably carried out on the filter hoses 3, which are located in the upper part of the container 1, so that the use of such filter hoses requires that the material agglomerate on their surface. The agglomerated fine ground falls back into the fluidized bed at a satisfactory rate of descent when cleaning the filter hoses.

The external separation of the fine powder carried by the exhaust gas is preferably carried out by means of a cyclone or a filter. In this case, the separated fine powder falls into a cell-wheeled sluice, which is required to maintain the pressure difference between the vortex bed and the dust separator. From this sluice, the fine grind is preferably returned pneumatically via a separate conduit via a propellant stream, preferably in the region of the nozzles, so as to ensure uniform growth of all particles in the particle size spectrum. Other conventional methods for even distribution in the fluidized bed can be ensured.

In the process of the present invention, a gas for fluidizing and solidifying the atomised material is introduced through the bottom of the fluidized bed granulator through the perforated flow bottom. Any conventional gas which is inert to the working conditions can be used as the fluidizing gas. Preferably, air and an inert gas, such as, for example, air are used. nitrogen.

The temperature of the fluidizing gas can be varied within wide limits. Usually we work at -20 ° C to +700 ° C, preferably 0-650 ° C,

The velocity of the fluidizing gas can also be varied within wide limits. Usually we work at gas velocities of 0.4-4 m / sec (speeds measured in empty tube). Preferably, the speed is 0.5-2 m / sec. The amount of fluidizing gas results from the velocity and density of the gas and from the cross-section of the particle size of the apparatus.

The fluidizing gas velocity is chosen to maintain a highly mobile vortex bed which does not, on the one hand, cause undesirable aggregation of the particles and, on the other hand, does not exaggerate the wear of the fluid bed and the extraction of solids from the bed.

The inflow bottoms in the apparatus are flat or funnel-shaped. Preferably, the inflow base is funnel-shaped and the aperture angle can be varied within a defined range. Preferably, the funnel has an opening angle of 140-160 °. If such an angled and perforated inflow bottom is used, where the perforations provide a radially inward flow, then, in particular, the larger particles in the fluidized bed will be led to an outlet tube centered in the middle of the inflow base.

However, there are other options for placing the flow bottoms and the grid. For example, the granulator may be rectangular with a flat or oblique bottom. Several classifiers distributed over the inflow surface can be used. Bottom segments may be flat surfaces or inclined towards the classifier. In a preferred embodiment, the bottoms have a polygonal cross-section. In the center of the bottom segments, in the embodiment of Figure 9, there is always a nozzle surrounded by an annular classifier. In this way, the classifier is built on several identical segments. With this arrangement it is possible to achieve the classification

HÜ 204207 Β frequency should remain constant regardless of equipment size.

As shown in Figure 3, nozzles 5 are located at the height of the fluidized bed through which the liquid material can be introduced into the vortex bed in a finely divided manner. Achieving and maintaining a steady state in the fluidized bed can be controlled through self-acting pressure drop. The pressure drop in the bed is indicated and registered by the pressure gauge 6. Deviations from the normal value indicate disturbances in the pelleting process. A discharge tube 7 is centrally located in the inflow base 2, with a zigzag classifier 8 integrated in the upper portion adjacent to the inflow base 2. An additional pressure regulator 9 is integrated between the zigzag grading outlet 8 and the fan 4. This pressure regulator 9 controls the fan 4 in such a way that at all times the output of the zigzag classifier 8 is controlled by a pressure which is only slightly less than the atmospheric pressure. In this way, another device related to the zigzag classifier, such as the zigzag classifier, can be omitted the lock. The finished granulate falls unhindered on the discharge tube 7 and is retained by the storage container 10.

Liquid material added to the vortex bed is sprayed from the bottom up in the process of the invention.

In the process of the present invention, dual nozzles are used to spray liquid material into the fluidized bed, which finely atomizes the liquid material and promotes good mixing of the fluidised bed. If the neutral point of the pressure profile lies at the outlet of the screen, vacuum is present. The nozzles can be replaced during operation without gas escaping into the environment. The air flowing into the granulator from the outside through the nozzle mounting aperture also prevents the material from escaping. In order to prevent air from entering the exchange during inert apparatus, an embodiment in which the inlet air is flushed with the atomising gas is preferred. Such an apparatus is shown schematically in Figure 8.

In this case, the gas for atomizing the liquid material is passed through a space formed by an auxiliary bottom b located below the flow bottom a. The sleeve c is welded to the bottom of the space for each nozzle f with a side bore d. The tube c is provided with a tube e which guides the nozzle f. The nozzle f of the nozzle f is so long that it extends upwardly from the bottom edge of the bushing c over the inflow bottom. The tube e is also provided with a side bore d so that by rotating the tube leading to the nozzles f, the nozzle gas can be led to the nozzle f, either completely or partially. When the nozzle f is pulled out of this tube leading to the nozzle f, so much spray gas must flow into the orifice so that no particles can fall out of the fluidized bed through this orifice and no ambient air can enter the granulator.

The double nozzle also has a hole in the side where the nozzle gas, after the nozzle is installed, can flow from the nozzle guide tube into the nozzle gas conduit.

The addition of the liquid material in the process 5 of the present invention is controlled by the exhaust air temperature as is customary for the granulators and the spray dryers.

As can be seen from Figures 4 and 5, the present invention. In the case of the apparatus, the zigzag classifier 8 consists of a plurality of rectangular channels 11 which are connected at an angle of 120 °. Channel 11 is flanked by zigzag-shaped plates 12. At the lower end of the zigzag classifier 8 is a gas distributor 13, which allows the same amount of gas to be supplied to each screening channel. A swirl roll is formed in each of the screening elements, which means here the section between two adjacent screening sites. The substance to be graded slides on the respective lower surface, passes through the screening gas stream, then moves upwardly on the respective upper surface and here again crosses the screening gas stream Each screening has a classification so that, although the screening elements are small, repetition allows us to create a high resolution.

When working with the 8 zigzag classifiers, it is extremely advantageous to have an adjustable cross-sectional classifier! 5, as depicted in FIG.

In the zigzag classifier, the required minimum throughput cross section of the screening section can only be determined experimentally as it depends on the particle size distribution of the bed and the exit granule stream. If the throughput cross-section is too small, the stationary operation of Fig. 1.35 is not possible because there is not enough granule to exit and in this case the bed load and grain size increase uncontrollably. If, on the other hand, the throughput cross-section is too large, it will not cause disruption to the granule formation 40, but this mode of operation may be energetically disadvantageous. To adjust the throughput cross-section, the adjusting mechanism 14 is used in the classifier (see FIG. 6). In the zigzag classifier, the length of the column and thus 45 the classification cross-section can be varied. The actuator 14 is comb-connected to each other, a. It consists of ribs fitting to a zigzag profile which can be displaced transversely, i.e. perpendicular to the screening axis, by means of 15 drives. The actuator 14 is connected to a regulator 50 16 which controls the screening gas flow through valve 17 such that the flow velocity in the zigzag classifier 8 remains constant despite the variable cross-section. The optimum setting of the actuator 14 is determined empirically by first determining the amount of screening gas flow required for the desired granule size when fully open. Meanwhile, the bedding automatically adjusts. The free grading cross section is then reduced using the adjusting device 14 until the bed is

HU 204207 nő increases the bed load measured with pressure drop. This gives the smallest screening cross section required for the pelleting process. For stationary operation, the cross sections of the classifier are selected slightly larger than necessary to ensure stable operating conditions.

An extremely advantageous apparatus for carrying out the process of the invention is shown in FIG.

For the granules obtained by the process according to the invention, the percentage of the components contained therein can be varied within wide limits. The proportion of active components can generally be from 1 to 100% by weight. When a melt or solution of the active substances is sprayed, the resulting granulate comprises up to 100% by weight of the respective materials, optionally up to 5% by weight of solution or solvent. When spraying liquids that contain other active ingredients besides the active components, e.g. containing inert fillers, dispersants, binders and / or other additives, the proportion of active ingredients is generally 5-95% by weight, preferably 10-80% by weight. The proportion of inert fillers is generally from 0 to 99% by weight, preferably from 0 to 95% by weight. Dispersants and / or binders and optionally further additives are generally present in an amount of 0-40% by weight, preferably 0-30% by weight.

In the granular particle according to the invention, the particle size is generally 0.1 to 3 mm, preferably 0.2 to 2 mm. The particle size of the granular particle according to the invention depends on its particular application. The particle size distribution is very narrow compared to conventionally produced particles. In general, the particle diameter of the secondary particle size of at most a half of vision of the middle részecskeátmérőtől (d _so).

The particles of the present invention are uniform in shape and high strength. Their structure is compact, microporous and nonetheless spontaneously dispersible or soluble in water or other solvents. By this is meant that in the present case the particles are generally completely dispersed or dissolved within 0.5-3 minutes, preferably 1-2 minutes.

The granules according to the invention can be used for a variety of purposes according to their active components. Particles containing agrochemical active ingredients as active ingredients may be used in the field of plant protection by conventional methods. Such granules are dispersed or dissolved in water. The dispersion or solutions thus obtained are optionally applied to the plants and / or their habitat, e.g. spraying, spraying or irrigation. The amount employed will depend upon the concentration of the dispersion or solution, the field of application, and the active ingredients contained.

If the granules according to the invention do not contain agrochemical active ingredients but contain other active components, the application is carried out according to the usual methods in the field. Again, the amount used will depend on the particular active ingredients and the indication of the particle.

In some cases, the granules produced by the process of the invention may be subjected to thermal curing, e.g. zeolite particles can be cured or activated by heating them to 300-700 ° C, preferably 350-650 ° C. Particles containing inorganic oxides which may be used as catalysts or catalyst supports may be cured by heating to 5001000 ° C.

The present invention is illustrated by the following examples.

Example 1

The dimensions of the apparatus according to the invention shown in Figure 9 are as follows:

The flow bottom has a diameter of 225 mm

The diameter of the relaxation area is 450 mm

The total height of the grater is approx. 2 mm

Atomizer Nozzles 1 Double Nozzle

The screen has a cross-section of 880 mm ²

Zigzag Classifier has 10 members

In this apparatus, an aqueous solution of salt, which contains 23% by weight of salt, is granulated. This solution was sprayed into a fluid bed granulator at 20 ° C. Air is inflated at 127.5 kg / hr to fluidize the bedding. The inlet temperature of the fluoridation gas is 180 ° C and the outlet temperature is 80 ° C. Air is used as the scavenging gas, of which 18 kg / h is injected. The temperature of the screening gas is 20 ° C. The fluid bed capacity is 3 kg and the pelletizing capacity is 1.5 kg / h. Free flowing bulk mass of the granules obtained 1075 kg / m ³ and the central particle size of ₀ dj = 1.5 mm. The particle size distribution obtained by the sieve analysis is shown in Fig. 7 with curve 1.

Example 2

In the apparatus mentioned in Example 1, an aqueous suspension is granulated. First, a powdery mixture of 2% isopropoxyphenyl N-methylcarbamate 2% magnesium oxide 4% highly dispersed silica 10% alkylarylsulfonate and 34% stone powder is blended with water to An aqueous suspension containing 60% by weight of a solid is obtained. This suspension is sprayed into a fluid bed pelletizer at 20 ° C. The granulation takes place under the following conditions.

Fluidizing gas: air gas throughput 127.5 kg / h inlet temperature ° C outlet temperature ° C

HU 204207 Β

Shale gas: air gas throughput 12 kg / h gas temperature 20 ° C

From bed. 1.2 kg 5

Peeling power 4 kg / h

Free-flowing granulate having a bulk weight of 785 kg / m ³ and an average particle size d = _{5 O} 0.7mm. The particle size distribution obtained by screening analysis is shown in curve 2 in FIG. 10

Example 3

In the apparatus described in Example 1, the melt is granulated.

The alpha polyglycol ether, which melts at 60 ° C, is sprayed into a fluid bed granulator at 70 ° C. The granulation is carried out under the following conditions.

Fluidizing gas:. air gas throughput capacity 127.5 kg / h inlet temperature ° C outlet temperature ° C 25

Shale gas: air gas throughput 8 kg / h gas temperature 20 ° C

Bed load 1.8 kg 30

Peeling power: 3 kg / h

A free-flowing granulate having a bulk weight of 535 kg / m ³ and a mean particle size of d ₅₀ = 0.36 mm is obtained. The particle size distribution obtained by screening analysis is shown in curve 3 in FIG. 35

Example 4

In the apparatus described in Example 1, an aqueous suspension (slurry) is granulated. A dual nozzle is used as a nebulizer and a zigzag autoclave is used as a screening device. The laceration is separated off by the cyclone.

First we create a mixture of the following components:

6% by weight of 6-phenyl-4-amino-3-methyl-1,2,4-triazin-45 5 (4H) -one, 5% by weight of alkylarylsulfonate 5% by weight of ground alumina by weight, based on lignin sulfonate dispersant

This mixture is mixed with water with stirring to give an aqueous slurry containing 65% by weight of a solid. This suspension is sprayed at 20 ° C with air into a fluid bed granulator. The granulation is carried out under the following conditions:

Humidifying gas: air gas throughput 130 kg / h inlet temperature 96 ° C 60 outlet temperature 60 ° C

Shale gas: air gas throughput 8 kg / h gas temperature 20 ° C

Diverter gas: air gas throughput capacity 9 kg / h

Granulation power: 2.4 kg / h A powder-free, free-flowing granulate having a bulk weight of 585 kg / m ^{3 is obtained} .

The granule particles are nearly spherical. The average particle size is d ₅₀ = 580 µm.

The granules dissolve in water in no time.

Example 5

In the apparatus described in Example 1, an aqueous suspension (slurry) is granulated. First a powdery mixture is prepared

N- (5-ethylsulfonyl-1,3,4-thiadiazol-2-yl) -N, N'-dimethylurea by mixing with water under constant stirring to give an aqueous slurry of 60% solids. This suspension is sprayed into a fluid bed granulator by means of a spray gas. The granulation is carried out under the following conditions.

Humidifying gas: Nitrogen gas throughput 127 kg / h inlet temperature ° C outlet temperature ° C

Shale gas: flow rate of nitrogen gas 9 kg / h gas temperature 40 ° C

Atomizing gas: Nitrogen gas flow capacity 6 kg / h Gas temperature 20 ° C

Propulsion gas (recirculation): nitrogen gas throughput 15 kg / h gas temperature 40 ° C

Granulation power: 3 kg / h A powder-free, free-flowing granulate having a bulk weight of 690 kg / m ^{3 is obtained} . Medium grain size d ₅₀ = 500 µm.

Example 6

In the apparatus described in Example 1, an aqueous suspension (slurry) is granulated. First a powdery mixture is prepared

N, N-dimethyl-N '- (fluordiklór-metilmeikapto) -N' - (4

-methylphenyl) sulfamide by mixing with water with constant stirring to give a solids content of 60% by weight.

HU 204207 Β aqueous suspension. This suspension is sprayed into a fluid bed granulator by means of a spray gas. Eyesighting is performed under the following conditions.

Fluidizing gas: Nitrogen gas throughput 127 kg / h inlet temperature ° C outlet temperature ° C

Shale gas: nitrogen gas throughput 11.5 kg / h gas temperature 40 ° C

Atomizing gas: Nitrogen gas flow capacity 6 kg / h Gas temperature 20 ° C

Propulsion gas (recirculation): nitrogen gas throughput 20.8 kg / h gas temperature 40 ° C

Granulation power: 3.8 kg / h A powder-free, free-flowing granulate having a bulk weight of 683 kg / m ^{3 is obtained} . Medium grain size _dso = 400 µm.

Example 7

In the apparatus described in Example 1, an aqueous suspension (slurry) is granulated. First, a mixture of porous carbon is prepared from 1- (4-chlorophenoxy) -3,3-dimethyl-1- (1,2,4-triazol-1-yl) butan-2-ol by stirring with so much water under constant stirring. to obtain an aqueous suspension containing 50% by weight of solids. This suspension is sprayed into a fluid bed granulator by means of a spray gas. Eyesighting is performed under the following conditions.

Fluidizing gas: Nitrogen gas throughput 127 kg / h inlet temperature ° C outlet temperature ° C

Shale gas: flow rate of nitrogen gas 11.5 kg / h gas temperature 35 ° C

Atomizing gas: Nitrogen gas throughput 6.5 kg / h Gas temperature 20 ° C

Propulsion gas (recirculation): nitrogen gas throughput 19 kg / h gas temperature 35 ° C

Granulation power: 2.5 kg / h A powder-free, free-flowing granulate having a bulk weight of 942 kg / m ^{3 is obtained} . Medium particle size d ₅₀ = 400 µm.

Example 8

In the apparatus described in Example 1, an aqueous suspension (slurry) is granulated. First, a powdery mixture of 1- (4-chlorophenoxy) -3,3-dimethyl-1- (1,2,4-triazol-1-yl) butan-2-one is prepared by stirring with so much water under constant stirring. to obtain an aqueous suspension containing 60% by weight of solids. This suspension is sprayed into a fluid bed granulator by means of a spray gas. Eyesighting is performed under the following conditions.

Fluidizing gas: Nitrogen gas throughput 127 kg / h inlet temperature ° C outlet temperature ° C

Shale gas: nitrogen gas throughput 25 kg / h gas temperature 40 ° C

Atomizing gas: Nitrogen gas flow capacity 6 kg / h Gas temperature 20 ° C

Propulsion gas (recirculation): nitrogen gas throughput 10 kg / h gas temperature 40 ° C

Granulation power: 1.5 kg / h A powder-free, free-flowing granulate having a bulk weight of 667 kg / m ^{3 is obtained} . Medium grain size d ₅₀ = 500 µm.

Example 9

In the apparatus described in Example 1, an aqueous suspension (slurry) is granulated. First a powdery mixture is prepared

N- (2-benzothiazolyl) -NN'-dimethylurea by stirring with water at constant stirring to obtain an aqueous suspension containing 50% by weight of a solid. This suspension is sprayed into a fluid bed granulator by means of a spray gas. Eyesighting is performed under the following conditions.

Fluidizing gas: Nitrogen gas throughput 127 kg / h inlet temperature ° C outlet temperature ° C

HU 204207 Β

Shale gas: Nitrogen gas throughput 15.5 kg / h Gas temperature 40 ° C

Atomizing gas: Nitrogen gas flow capacity 6 kg / h Gas temperature 20 ° C

Hair gas (recirculation): nitrogen gas throughput 21 kg / h gas temperature 35 ° C

Granulation power: 3.3 kg / h A powder-free, free-flowing granulate having a bulk weight of 575 kg / m ^{3 is obtained} . Medium particle size d ₅₀ = 1000 µm.

Example 10

In the apparatus described in Example 4, an aqueous suspension (slurry) was granulated. First, a mixture of dust grains is prepared

97.5% by weight of 4-amino-6- (1,1-dimethylethyl) -3-methylthiol, 2,4-triazin-5 (4H) -one by mixing with water so that an aqueous slurry of solids is obtained. This slurry is sprayed into a fluid bed granulator using a spray gas. The granulation takes place under the following conditions.

Hypnotic gas: Nitrogen gas throughput of 127 kg / h inlet temperature

100 ° C exit temperature ° C

Shale gas: flow rate of nitrogen gas 11.5 kg / h gas temperature40 ° C

Atomizing gas: Nitrogen gas flow rate 6.6 kg / h Gas temperature20 ° C

Propulsion gas (recirculation): nitrogen gas throughput 14.5 kg / h gas temperature 40 ° C

Pelletizing power: 4.5 kg / h Dust free, free flowing granules 50 with a bulk weight of 530 kg / m ^{3 are obtained} . Medium grain size d ₅₀ = 450 µm.

Claims (6)

A process for the continuous production of granules having a grain size of 0.1 to 3 mm by spraying, characterized in that: (a) spraying the material to be granulated in a fluidized bed, b) separating the sinter fracture leaving the fluid bed with the exhaust gases and returning it to the vortex bed as a crystal germ to form a granule, C) controlling the pelletizing process in the fluidized bed solely by adjusting the screening gas flow so that the granules are produced in the size given by the screening gas stream, wherein the amount of the screening gas is 0.2-5 kg / kg and the speed of the screening gas is 0, 5-15 m / sec, then (d) the finished granulate operates solely on the basis of one or more counter-gravity forces placed in the flow bottom of the fluid bed apparatus; We take them out of 15 classifiers and e) optionally subjecting the granulate thus obtained to a thermal post-treatment at a temperature of 300 to 1000 ° C. A process according to claim 1, wherein the liquid to be granulated comprises one or more active components. 3. A process according to claim 2, wherein the active ingredient is agrochemicals, household or hygiene agents, pharmacologically active substances, nutrients, sweeteners, dyes, organic and / or inorganic chemicals. The method of claim 1, wherein 30, that the fine powder leaving the fluid bed is continuously separated from the exhaust gases by cyclone or dust filter and recycled to the fluidized bed or by means of a dust filter placed above the vortex bed to provide internal fine powder recycling. 35 5. The method of claim 1, wherein the zigzag classifier is adjustable with one or more adjustable column lengths. 6. A process according to claim 1, characterized in that the finished granulate is equipped with a nozzle and a grater It is taken over 40 fitted, mid-inclined multi-hexagonal flow bottoms.