JP5021129B2 - Compression molding equipment for bulky items - Google Patents

Description

[0001]
The present invention relates to a bulky article having a roller press and a screw conveyor disposed on the upstream side of the roller press with a feeding hopper as a bulk goods feeding device mounted thereon. The present invention relates to a compression apparatus for use.
[0002]
Crude products supplied as powders, granules or mixtures thereof are sometimes not suitable for further subsequent processes such as tableting in the pharmaceutical industry. This is because the raw product has a very high proportion of air and / or lacks sufficient fluidity. It is known in the patent (German Patent 3431865 C2) to compress the green products before further processing and subsequent granulation of them, but in particular practically Absent. For example, a roller press with a screw conveyor for compression molding is installed before use. Using a screw conveyor, the raw product is fed from the feed hopper into the roller gap under a certain pressure.
[0003]
Since the roller press is sealed on both sides and the conveyor is hermetically connected to the roller gap, the air expelled from the raw product during compression will pass through the raw material in the screw housing in the direction of raw material transport. Must move in opposition. Although air may subsequently flow out through a raw material column located in the supply hopper, the raw material column is resistant to air as a function of height and density. However, some of the air can “explosively” pass through the roller gap, so the roller press is operated under load and generating nozzles.
[0004]
In compression molding, the flakes formed during compression molding should be as homogeneous as possible. This is because this property has a direct impact on the final product. If the raw product in the feed hopper is not evenly distributed with respect to grain size or other characteristics, heterogeneous flakes will occur. This occurs particularly when a portion of the compression-molded raw material that does not have a predetermined grain size after granulation is recycled to the supply hopper. This direct recycle of the compression molded raw material is not without problems. This is because the bulk specific gravity of this compression molded raw product is very different from the bulk specific gravity of the unprocessed raw product.
[0005]
An untreated raw product with a bulk specific gravity of 200 g / l may have a bulk specific gravity of 800 g / l as a recycled material after compression molding. This greatly fluctuates the mass flow rate of the recycled product. In soft flakes, the proportion of the mass flow rate of the recycled product fed to the roller press is large, which has a positive effect on the homogeneous quality of the flakes, but the mass flow rate of the recycled material does not. Results in being lost. Therefore, stabilization of flake quality is only brought about by a slow process.
[0006]
For this reason, to date, the mass flow rate of the recycled material has undergone a corrective mixing process with the raw product before compression molding.
Further, a compression molding apparatus for bulky products is known (German Patent Application Publication No. 3806398A1 ( German Patent Application 3806398 A1)), a supply hopper having two shafts may be arranged above the roller press, and various types of bulk goods may be supplied in parallel from the shaft to the roller gap. The proportion of different types of bulky items fed from different shafts to the roller gap may be adjusted by a metering element. The bulky product that has passed through the roller gap is crushed and partially agglomerated, ie compressed into flakes. In general, flakes are ground in a ball mill for final processing, and further fed to a moving device. The inferior product is recirculated as a fine-grained product to a shaft that has a fine-grained product feeder. Is done. The degassing of the bulky item is performed via a raw material column in the shaft for the bulky product that is the product.
[0007]
It is an object of the present invention to provide an apparatus for compression molding granulated products and granulated products, which produces a compression molded product as homogeneously as possible.
[0008]
This object is achieved by the compression molding apparatus described below according to the present invention.
In compression molding equipment:
The supply hopper has at least two shafts that are located back and forth in the conveying direction of the screw conveyor, from which the screw conveyor is fed with various types of bulky items and is downstream in the conveying direction. From the bottom to the end of the shaft;
A granulating device having a granulating material separating device is connected to the downstream side of the roller press and separates the granulated material by the grain size;
Recirculation of the granulate which is not suitable for the next process takes place from the separating device in the conveying direction to the front shaft.
[0009]
By using the compression molding apparatus in the present invention, homogeneous flake quality is assured throughout the entire manufacturing process. For this purpose, raw products and further components are supplied from the various shafts in parallel to the screw conveyor from the beginning. This makes it possible to feed only a part of the constituent material from the front shaft (one or more) to the screw conveyor in the conveying direction, while allowing raw products to be filled from the rear shaft into the screw conveyor. ing. A multi-threaded screw conveyor that contains the granulated material recirculated by the separator, and that provides the optimum mixing of the raw material to be compression-molded by feeding each raw material in the conveying direction of the screw conveyor. Brought about by collaboration. With regard to deaeration, the following is preferred and the expelled air does not have to pass through the generally full feed column in the back shaft, but rather in either of the upstream shafts. It only needs to pass through a small, generally empty, raw material column.
[0010]
The proportion of raw material that is unsuitable for the next process and has to be recycled is generally small and the feed hopper shaft containing this raw material is only partially filled anyway, Deaeration through this shaft is possible without resistance.
[0011]
Preferably, the upstream first shaft is supplied with a granulated product having larger grains. “Bigger grain” means larger grain compared to the raw product. It has been found that this material is suitable for screw cleaning and also plays a role in assisting feeding in roller presses.
The present invention will be described in detail below with reference to the drawings.
[0012]
The compression molding apparatus is composed of a raw product compression molding part 1, a granulated part 2, and a granulated product separating part 3.
[0013]
The first part 1 includes a roller press 4 having a horizontal material supply device. The material to be compression-molded is supplied to the roller gap of the roller press 4 under pressure through the screw conveyor 5, and the screw conveyor 5 mixes the supplied material with a screw housing 5a and a multi-thread screw 5b. And have. The screw conveyor 5 is hermetically connected to the roller gap.
[0014]
The roller press 4 is sealed laterally by a cover plate 6. A supply hopper for granulated / granulated products divided into a front shaft 7 and a rear shaft 9 is arranged above the screw conveyor 5. The rotor 8 is attached to the inside of the shaft 7 so that the raw product moves so as not to stay in the shaft 7.
[0015]
The granulated raw product is introduced into the shaft 7. A screw conveyor 5 feeds the raw product into the roller gap of the roller press 4 under pressure, where the raw product is compression molded into flakes S. The flakes S are subsequently granulated in part 2 of the device. Since the granulated product G is usually a wide granular pallet, it is not suitable for the subsequent processes. Thus, in a continuous part 3 of the apparatus, the granular pallet is separated into a granulation G1 suitable for the subsequent process and a granulation G2 which is recycled to the shaft 9 of the feed hopper. Since the mass flow rate of the granulated product G2 is small, the screw conveyor 5 is only partially supplied with it. The remainder of the supply is raw material in the shaft 7. Thus, even in the early stages of the production process, the screw conveyor is fed in parallel with materials of various properties from both shafts 7,9. This has a positive effect on the desired homogeneous flake quality.
[Brief description of the drawings]
FIG. 1 is a partial schematic view of a compression molding apparatus.

Claims (3)

A roller press (4), and a screw conveyor (5) disposed upstream from the roller press (4) and having a supply hopper as a supply device for a bulky article disposed above, In compression molding equipment for bulky items:
The supply hopper has at least two supply hoppers (7, 9) arranged back and forth in the conveying direction of the screw conveyor (5), from the supply hopper (7, 9) to the screw conveyor In (5), various types of bulk goods are supplied and supplied in parallel from the lower part of the supply hopper to the subsequent supply hopper (7) in the conveying direction . 9) to the screw conveyor (5) in the conveying direction, different materials are supplied in parallel, and raw products are supplied in the conveying direction from the subsequent hopper (7) to the screw conveyor (5). Have been
A granulating device (2) having a separating device (3) for the granulated product (G) is connected to the downstream side of the roller press (4), and separates the granulated product (G) by grain size. And the granulation device has a recirculation guide, which connects the separation device (3) and the feed hopper (9) in the preceding stage in the conveying direction, The granulated product (G2) that is not suitable for the above process is recycled in the conveying direction to the preceding feed hopper (9), and the recycled granulated product (G2) is recycled in the conveying direction to the preceding feed hopper. Being supplied to the screw conveyor (5) from (9),
A compression molding device characterized by   The compression molding apparatus according to claim 1, characterized in that the screw conveyor (5) is a multi-thread screw for bulky product mixing. The compression molding apparatus according to claim 1 or 2, wherein the supply hopper (9) at the front stage is supplied with a granulated product (G) having larger grains.

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