DD155587A1 - TWO-OR MULTIPLE SWIVEL LAYERING APPARATUS FOR GENERATING GRANULES - Google Patents

Abstract

The invention relates to a device for the continuous production of two- or multi-layered granules in an apparatus with low energy and investment costs. The invention is intended to achieve the production of two- or multi-layered granules with a precisely defined granule diameter or enveloping layer thicknesses. This is possible by connecting the individual superimposed vortex chambers to one another with classically acting granules. These pellets have externally controllable cross-sections, with which an adjustment of the desired grain fraction or Umhülungsschichtstaerke is possible. The amount of air in the upper vortex chambers is regulated by means of two air nozzles.

Description

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Two- or multi-stage fluidized bed apparatus for the generation of granules

Field of application of the invention

The invention relates to fluidized bed apparatus which are preferably used for the production of multi-layered granules in the fertilizer and pharmaceutical industries.

Characteristic of the known technical solutions

Either multi-layered granulation devices are known in which granules of the desired size are placed in a single stage fluidized bed apparatus and coated by spraying with a different type of material (SU Pat 352,861, SU Pat 239,358). A disadvantage of these devices is that the production of Grundgranalien must be done in another apparatus and only then the sheath can be done in the single-stage fluidized bed apparatus. ,

T / eiter is known a two-stage device for granulating and wrapping, which has no perforated bottom between the forming layers, but form the superimposed fluidized beds by different gas velocities. These different gas velocities are achieved by a burner located between the layers.

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testifies. After reaching a desired size of the starting granules fall into the underlying layer and are wrapped here with different types of material and then subtracted laterally. The disadvantage here is that the materials used must be heat resistant. Due to the lack of Zwischenbod'ens may continue to come back remixing phenomena. A well-defined diameter of the final product is not possible due to the lateral withdrawal (US Pat.

In addition, single-stage devices are known in which granules can be produced from melts, solutions and suspensions in the fluidized bed. A simultaneous wrapping with a differently -gearteten material is not possible because of the only one operation. The enclosure must be in a separate apparatus (SU Pat., 201,233, SU Pat., 208,701, SU Pat., 515,523, U. S. Pat., 3,475,132, U.S. Pat., 3,794,099, U.S. Pat., 3,793,740) ).

There are also multi-stage fluidized bed apparatuses are known in which the granules fall over a kind of overflow weir on the lower ground. In this case, compliance with a narrow grain spectrum is not possible because of the different residence times of the granules (Beranek et al., "Fluidized Bed Technology", Leipzig 1975);

Object of the invention

The aim of the invention is to find a two- or multi-stage fluidized bed apparatus for granulation, which does not have the deficiency described.

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Explanation of the essence of the invention

The invention has for its object to provide a two- or multi-stage device for the continuous production and uniform coating of granules with a narrow range of grains in one operation with low energy consumption and investment costs. The inventive device consists of two or more superimposed vortex chambers, each having a perforated bottom at the bottom. In the following, a two-stage apparatus is described.

^s , wrote, in a multi-stage apparatus, the arrangement is analogous. The upper classifying-acting trigger has an operable from outside the device actuator for changing the discharge cross-section and thus controlling the amount of air. In the upper vortex chamber an atomizing device for the production of the basic granules is arranged. In the lower vortex chamber, a spraying device for the wrapping material is installed. The lower vortex chamber further has a side-mounted two-air nozzle with sailing device and a classifying-acting granulate trigger iflit rotary valve. At the foot of the device is an air inlet chamber with conical transition piece and air inlet nozzle attached.

'orders. At the head there is the conical transition piece "and the air outlet chamber with outlet nozzles.

In the upper vortex chamber granules, consisting of the base material, are kept in the T / irbelzustand due to the air flowing through the upper fluidized bed granules. The atomizing device is used to spray melt, solution or suspension of the base material onto these granules via the atomizing device, resulting in an increase in its diameter. The vortex air flows through the upper conical transition piece, the air outlet chamber and the air outlet nozzle from the device. The granules

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After the desired diameter has been reached, the upper vortex chamber falls through the classifying-acting draw-off into the lower vortex chamber. The air velocity in the upper granulate exhaust pipe corresponding to the respective granule diameter is adjusted by adjusting the associated control element of the take-off cross section, whereby a classification of the granules is achieved.

In the lower vortex chamber, the supply of the wrapping substance is effected via the atomizing device, whereby a coating of the initially introduced basic granulate is effected. If the wrapper has the desired layer thickness, i. the coated granules reaches the desired diameter, the coated granules fall through the exhaust pipe, where the controllable exhaust air flows through the exhaust air nozzle to the granules and thus causes a classification. The granules of the lower swirl chamber are maintained in a fluid state by fluidizing air flowing over, the air inlet nozzle, the air inlet chamber and the lower conical transition piece. This turbulent air, after flowing through the upper fluidized bed, simultaneously serves to swirl the granules on the upper fluidized bed. The secondary air needed to control this process is introduced via the secondary air connection with control.

The invention will be explained with reference to an embodiment.

In a two-stage device with a diameter of the perforated trays 1 and 2 of 0.4 m and a total height of 5i5 υ 0.05 nr / h urea melt are sprayed into the upper vortex chamber 3 by means of a nozzle with feed line 4 on the fluidized bed. After growth of the granules to the desired diameter of 3 mm they fall through the upper classifying-acting trigger 5 with control member 6 in the lower vortex chamber 7. In this, the Aufdüsung of 0.1 nrVh 70% active ingredient

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solution to the urea base granules by means of a nozzle system 8. After the coating strength of the active ingredient has increased to 0.5 mm, i. The total diameter of the granules is 4 mm, they drop out of the device through the lower, classically acting trigger 9 and are drawn off with the rotary feeder 10

The turbulence serving air (1000 nr / h) is heated to 70 ⁰ C and passed through the air inlet chamber 11 in the apparatus. The second air addition (150 m- / h) takes place through the second air connection with regulation 12.

Claims (1)

- * - 2 2 6 U 4 9 invention claim Two-stage or multi-stage fluidized-bed apparatus, characterized in that the superposed vortex chambers (3) and (5), which can have constant or altered cross-section with each other by one or more centrally or offset in the fluidized bed (1) arranged classifying granule (5) connected with variable cross-section and in each vortex chamber atomizing means (4) and (8) and except in the uppermost vortex chamber (3) second air nozzle with control (12) are mounted. For this 1 page drawings