DE1939100A1 - Process for agglomerating a powdery material - Google Patents

Description

July 14, 1969 H / th

• 19th

INDUSTRIE-WERKE KARLSRUHE Public Company;

7500

Karlsruhe

Qartenstrasse 71

Method of agglomerating a powdery

Materials

The invention relates to a method for agglomerating a powdery material using a nozzle designed with an annular gap. _:

There are already processes for producing voluminous, but granular powder aggregates have been suggested. Such methods can be essentially divided into two Divide groups:

In one group, agglomeration takes place in one moving powder bed by spraying liquid mist or steam or by the fact that strongly water-

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vaporous "air is passed through a powder bed. The powder bed is moved mechanically Paths, for example through vibration or rotation.

In such processes, the agglomerate is formed already in the powder bed, so that agglomerates and powder coexist. This in turn inevitably requires a sifting and / or sieving of the fine powder at the end of the agglomeration process and a renewed run of the unagglomerated powder through the agglomeration apparatus.

In the other group, agglomeration takes place outdoors Fall or in the pneumatic air flow. The finely powdered starting product is in this procedure in a preferably vertical tube by means of a liquid mist or steam is wetted and then agglomerated. That way recovered powder agglomerates are then used. suitable apparatuses after-dried.

The agglomeration equipment required to carry out these known processes is of the type for manufacture to be distinguished from compact granules, the latter the forces exerted on the particles are generally much greater. *

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Compared to these known methods, the present Invention set the task of creating a method that allows the production of voluminous, but granular Powder units with porous outer surfaces and large inner surfaces are used, the powder units consisting of a fine powder or fine powder mixtures with the addition of water vapor or vapor of appropriately suitable organic solvents exist in which the starting material to be treated is soluble or swellable.

This object is achieved according to the invention essentially in that the powdery material or the material mixture to be fed to the nozzle is first subjected to a grinding and / or mixing process and then brought into a liquid state, whereupon the pretreated material of the central bore of the nozzle while the agglomeration agent is added at the same time, it then leaves the nozzle with a concentric twist in the same direction as the material flow, after which the material is loosened on its surface under the influence of the agglomeration agent and brought together under the influence of the baffle effect in such a way that a compression knot is formed in which additional nor liquid mist or the like can be introduced by means of a second nozzle that is independent of the first nozzle.

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in an advantageous embodiment of the invention is after a Another feature provided that the agglomeration agent consists of water vapor, water vapor-air mixture, organic solvent vapor or organic solvent vapor-Luftgeraisch.

According to another feature, the invention provides that in the resulting agglomerates, while they are still free falling, a secondary liquid component. is puffed up.

Furthermore, the proposed invention provides that that too agglomerating material from a mixture of different consists of powdery materials. '

The proposed invention is rounded off and perfected Finally, according to a last characteristic, that the resulting powder aggregates in a vibrating fluidized bed by means of dehumidified air at room temperature be re-dried.

The proposed invention has many advantages along with: "-"

The powder aggregates produced are characterized by lower debris weight compared to the finely powdered starting product, absolute freedom from dust, excellent wetting

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and dissolving properties as well as better flowability and a more natural appearance. The inventive Process achieves these improvements without otherwise adversely changing or affecting the desirable physical and / or chemical properties of the starting materials bze. their solutions or dispersions to have to accept. For example, neither the viscosity nor the taste, smell or the stabilizing Effect or any other properties of the original. substances changed in any way.

It should be particularly emphasized that the after the proposed Process produced powder aggregates also in large quantities and all at once with the appropriate solvent, in particular Water, can be brought together without causing undesirable Clumping phenomena occur as the agglomerates immediately soak up the solvent and into their Individual components with a mutually repelling effect disintegrate.

As a result of a suitable twisting of the steam slide, the Powder at the nozzle mouthpiece passed through a compression knot, on which on the one hand by the condensation of the Steam and, on the other hand, due to the mutual proximity of the particles, the desired powder aggregates without a residual proportion of painful powder arise within a fraction of a second

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The axis of the agglomeration nozzle is expedient inclined so that the powder aggregates produced sink in a trajectory parabola.

Another advantage of the method according to the invention is it also says that 'in the sinking agglomerate eggs, but also directly at the powder knot, by means of a second *

Suitable fluid addition to the first dependent nozzle

be sprayed on or sprayed to increase the strength and - at

ι ■ ■ - ■■ -.

F certain substances - the aroma content and other essentials To improve the properties of the powder aggregates obtained.

The agglomerates produced in this way in a still atmosphere come under braking by air flowing in the opposite direction on a mechanically moved fluidized bed. In contrast to known processes, this fluidized bed was not used for agglomeration, but the re-drying of the agglomeration - moistened powder aggregates. Because in this vortex ^ bed only agglomerates that are not surrounded by powder, this fluidized bed is homogeneous; dust formation is largely ruled out.

After drying, the agglomerates arrive _; on a sieve built into the same housing, through which the particles are passed using a suitable rotary brush. The amount of dust generated during this process is extremely low

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lind can remain in the product in most cases. Through this Is ensured that apart from a small amount of dust losses during drying and possibly subsequent cooling in Fluidized bed the entire powder the agglomeration process only once «and that only runs for a fraction of a second, so it is extremely gentle on the product.

The proposed invention has a particular advantage finally also in the fact that the agglomeration effect can be controlled by change, such as variation, of the Vectors -.

- powder fineness of the starting product,

- Adjustment of the shower gap,

- amount of steam and temperature,.

- Amount of conveying air in the central powder channel, · - Admixture of air to the steam as well

- Type, quantity and fineness of the additional liquid mist

can be done ..

The agglomerates are dried in particular with dehumidified air at room temperature, so that a subsequent Cooling of the agglomerates is not necessary and thermal damage to the sometimes very sensitive active ingredients, in particular When it comes to food, madness is avoided. at For suitable products, thermal drying is of course also provided.

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Claims (1)

19391OO Patent claims ■ '. 1.) A method for agglomerating a powdery material using a nozzle designed with an annular gap,
characterized, that the powdery material or material mixture to be fed to the nozzle is initially a grinding and / or Mixing process · subjected and then into a pseudo-liquid Is brought state, whereupon the pretreated material of the central bore of the nozzle with simultaneous addition of the agglomeration agent is fed to then leave the nozzle with a concentric twist in the same direction as the material flow, with then the material is partially dissolved on its surface under the influence of the agglomeration agent and under the influence of the swirl effect is brought together in such a way that a compression node is formed in which additionally nor liquid mist or the like can be introduced by means of a second nozzle that is independent of the first nozzle can. 2.) Method according to claim 1, characterized, that the agglomeration agent consists of water vapor, water vapor-air mixture, organic solvent vapor or an organic solvent vapor-air mixture. BATH ORIGINAL. J5.) Method according to claim 1 and 2, ^ characterized, dai3 into the agglomerates formed during whose free fall a fog-shaped liquid component is sprayed in or out. 4.) Method according to claim 1 to 3 *, characterized in that. that the material to be agglomerated from a straight line consists of various powdery materials. 5) Method according to one or more of the preceding claims, characterized in that the resulting powder. aggregates re-dried in a vibrating fluidized bed using dehumidified air at room temperature will. BATH ORIGINAL