DE1057031B - Device for separating fines from pourable masses - Google Patents

Description

Device for separating the fines from pourable masses of the fertilizers used in agriculture, it is required that they do not Contain fine particles so that they are free-flowing and do not generate dust.

The safest and sharpest separation of the fines can be done with the help of can be achieved by sieves, but the use of sieves is less than 0.5 mm mesh size difficult for bulk goods because such narrow sieves clog up too easily, too if you keep it in a shaking motion.

The separation of the fines with the help of air separators is expensive and not sufficiently selective, also in the wind sifter due to material fragmentation Fine fractions generated.

In addition to the devices for sieving, another classifier is known, in which the granular material to be classified by inclined, one below the other Vibrating sieves fall, whereby only the fine fraction should have a chance - through all sieves to fall through, while the coarser parts in the direction of the inclined Sieves should be deflected. As expected, however, with this device a sharp separation is not achieved.

The invention relates to a device for separating the fines from a pourable granular material. It consists of an inclined and with transverse slots provided plate (Fig.l), on which one lets the material to be separated trickle down. In the process, the fine fraction separates downwards and is discharged through transverse slits. The width of the slots can be several times the grain diameter of the material to be deposited Be fine, from which it can be seen that this is not a sieving process acts. It is essential that the inclination of the plate is as great as the angle of repose of the unseparated good, which is just coming to a standstill (angle a in Figs. 1, 2 and 3).

The selectivity is surprisingly high in one operation and can be increased by repeating the same operation; included the plates can be arranged one behind the other or one below the other (Fig. 2). You can start with relatively wide slots on the plate and they then let it become tighter (Fig. 3).

If the granular material is left at a steeper angle than when it is at rest measured slope angle trickle down the plate, the material remains insufficient together, and the separation of the fines becomes imperfect.

The extent to which success depends on maintaining the inclination of the plate can be seen from the tests numerically reproduced below, in which the same potash fertilizer salt, whose angle of repose measured at rest was 32 ° and which is about 50 ° / a proportions below 0.5 mm contained, with the aid of the device according to the present invention at different angles of inclination: under otherwise identical conditions, the salt fractions' below 0.5 mm were separated. Separation of the salt fractions below 0.5 mm from a potash fertilizer salt, which contained about 500% of it diameter 31'_ 32 1 33 ° 35 0 400 mm 0/0 0/0 0 @ 0 0% 0 0 @ greater than 4 27.55. 21.46 23.15 21.02 15.49 3 to -4 20.65 - 22.74 21.48 18.65 18.10 2 - "3 23.97 21.98 23.15 21.91 19.55 1 "2 19.83 23227 21.14 19.33 17.96 0.5 "1 6.34 10.08 9.56 12.73 16.91 0 "0.5 1.66 0.47 1.52 6.36 11.89 100.00 100.00 100.00 100.00 100.00 The test results show that the potash fertilizer salt poured over the plate under the same conditions was surprisingly only cleaned satisfactorily from fine salt under 0.5 mm at its angle of slope of 32 ° measured in the resting state.

One can also see from the figures that the area of inclination of the plate, in which the proportion of 0 to 0.5 mm is almost completely excreted, extraordinary is small and therefore could not be easily found, if not how is made attentive by the present invention.

One might argue that the salt will only come under a somewhat steeper one Angle than the angle of repose measured at rest. Indeed work the known rigid inclined sieves all at an angle which is steeper than is the angle of repose. In the present invention, that comes to the fore abandoned:. Güt after an initial faltering again in motion, which eventually turns into a rapid trickle. This surprising observation may be explained in such a way that the pourability of the goods improves to the extent that how the fine is removed.

The device according to the present invention operates more economically than the previously known devices; as it does not contain any mechanically moving parts and, in addition to an excellent effect, allows great performance.

Example 1. A potash fertilizer salt artificially composed in its grain size with an angle of repose of 33 ° measured at rest was passed once over a plate with an inclination of 32 ° in an amount of 2500 kg / m2 per hour. The plate was 26 cm wide and 106 cm long and had transverse slits 2.5 mm wide at a distance of 15 mm. The salt would be separated on its way from the fine salt, which passed through the slits and collected separately under the plate, as the following grain analyzes show. Grain diameter task flow overflow % ° / ° ° / ° 4 to 5 15.4 0 21.46 3 "4 15.4 0 22.74 2 "3 15.4 0 21.98 1 "2 15.4 2.94 23.27 - 0.5 "1 15.4 20.59 10.08 0.25 "0.5 7.7 13.73. 0.26 0.12 "0.25 7.7 31.37 0.16 - 0.06 "0.12 7.6 31.37 0.05 100.0 100.00 100.00 A graphical evaluation shows a grain size of 0.87 mm with 7% faulty grain in the overflow and in the - pass. .

Example 2 A potash fertilizer salt artificially composed in its grain size with an angle of repose of 33 ° measured at rest was passed once over a plate with an inclination of 33.5 ° in an amount of 3850 kg / m² and hour. The plate was 26 cm wide and .100 cm long and now had transverse slots 1.25 mm wide at a distance of 15. Grain diameter task flow overflow mm ° / o ° / o ° / o > 5 13.13 0 14.87 4 to 5 13.13 0 13.66 '3 "4 13.13 0 14.63 2 "3 13.13 0 16.07 1. "" 2 13.13 0 15.35 0.5;, 1 13.13 11.43 13.19 0.25 "0.5 . 6.68 19.05 4.80 0.12 "0.25 6.68 38.10 5.04 0.06 "0.12 6.68 30.48 2.15 <0.06 1.18 0.94 0.24 _ 100.00 100.00 100.00 A graphical evaluation shows a grain size of 0.49 mm with 12% faulty grain in the overflow and in the throughput.

Example 3 A sand artificially composed in its grain size with a slope -, - angle of 32 ° measured at rest was passed once over a plate with an inclination of 31 ' in an amount of 4250 kg / m2 and hour. The plate was 26 cm wide and 106 cm long and had transverse slits 2.5 mm wide at a distance of 15 mm. Grain diameter task flow overflow mm ° / o ° / o ° / o 4 to 5 5.62 0 8.18 3 "4 10.57 0 16.35 2 "3 16.87 0.25 30.61 1 "2 20.25 8.98 29.71 0.5 "1 20.25 33.92 11.96 0.25 "0.5 20.25 43.64 2.59. 0.12 "0.25 5.62 12.09 0.40 _ 0.06 "0.12 0.34 0.87 0.10 <0.06 0.23 0.25 0.10 - 100.00 100.00 1.00.00 The graphic evaluation shows a grain size at 0.92 mm with 130 /, missing grain in the overflow and in the run. Example 4 A sand artificially composed in its grain size with an angle of repose of 32 ° measured at rest was passed once over a plate with an inclination of 40 ° in an amount of 6600 kg / m² and hour. The plate was 26 cm wide and 106 cm long and had transverse slots 2.5 mm wide at a distance of 15 mm. Grain diameter task flow overflow mm ° / ° °% ° 4 4 to 5 5.62 0 4.92 3 "4 10.57 0 10.37 2 "3 16.87 0.74 20.95 1 "2 20.25 2.21. 24.10 0.5 "1 20.25 23.16 20.62 0.25 "0.5 20.25 49.63 15.96 0.12 "0.25 5.62 21.32 2.89 0.06 "0.12 0.34 1.84 0.13 <0.06 0.23 1.10 0.06 100.00 100.00 100.00 A graphical evaluation results in a grain sheath at 0.57 mm with 22% faulty grain in the overflow and in the throughput.

A separation of substances on a fixed inclined surface is already the subject of German Patent 286 261, in which the to be separated Well over, a stair-shaped inclined grate screen is passed. Here is however, the slope of the surface is not limited to the angle of repose, and it will In contrast to the present invention, each particle is given the conscious opportunity to according to its size to fall through the .Rost or not, whereby the process is characterized as sieving.

Also in the United States patent 781 493 a separation on a fixed inclined plane is proposed, which is formed from rods or wires. This is also a sieve and not a classification in the sense of the invention, because here, too, each particle is given the opportunity to fall through the gaps formed by the rods or wires.

The drawing of the French patent specification 975 068 can give the impression arouse as if the process according to this patent was essentially identical to the present one Invention. However, as can be seen from the description, this is not the case about the classification of a uniform substance, but about a rough separation of heterogeneous mixtures such as garbage and vegetable waste. This procedure is coordinated on the different behavior of hard and soft substances that make up these mixtures exist. In order for a success to be achieved, the separating surface should be used to brake the soft parts of the mass roughened and under a test to be determined Incline to be erected. At no point in this patent is there any mention of one particularly favorable effect of a slope said to be equal to the angle of repose is, which is also not the case with a heterogeneous mass. As from the drawing can be seen, on the contrary, there must be a relatively steep slope of the roughened Separating surface are applied, otherwise the mass would get stuck.

Also in the French patent 485 844 are fixed inclined parting surfaces applied. Have the use of slots and holes here the purpose of separating round and flat grains from each other. Here too In contrast to the present invention, each individual particle is intended to have the opportunity be given to be separated through the gap or through the perforation.

With the separation of granular material into a fine and a coarse fraction German patents also deal with fixed inclined surfaces 673 327 and 609 990. In both cases it should roll down an inclined surface Material broken up by mechanical resistances and the top layer the embankment can be removed as coarse-grained. In contrast to the device according to According to the present invention, the slope of the surface becomes steeper than the slope angle held. The success of the separation in these devices depends essentially on it from how large the discharge slots are for a given feed quantity. With these Devices can only be separated parts that are capable of on the residual mass to roll. A further separation as in the examples of the present invention is not possible with these devices.

Claims (3)

PATENT CLAIMS: 1. Device for separating the fines from pourable masses, in which the granular material to be separated over a fixed Plate trickles, characterized in that the inclination of the plate is kept so great is like the angle of repose of the feed material measured at rest. 2. Device according to claim 1, characterized in that the width of the slots, from the feed side seen from here, decreases. 3. Apparatus according to claim 1, characterized in that several classifying surfaces with the same or different width slots are arranged below one another. Considered publications: German Patent Nos. 673 327, 609 990, 286 261; French Patent Nos. 975 068, 485 844; USA. Pat. No. 781,493.