JPS6314940Y2 - - Google Patents

Description

[Detailed explanation of the idea]

The present invention relates to a sieving device for powdered lumps, and more particularly to a sieving device with excellent screening efficiency. Generally, ores and other raw materials have a relatively wide particle size distribution, and when using them, they must be sieved in advance using a sieving device to a predetermined particle size range determined by the place of use, and then Supplied to processing steps. In this case, it is necessary to prevent as much as possible the contamination of particles of a size below the screening point onto the sieve and the contamination of particles of a size exceeding the screening point below the sieve as this will have an adverse effect on subsequent processes. A conventional sieving device for powdery lumps will be explained with reference to FIG. That is, the powder lumps 2 stored in the yard are discharged by a reclaimer 4, transported by a conveyor 6, and stored in a storage tank 8. The powder lumps 2 stored in the storage tank 8 are discharged by a cutting device 10, and are supplied to a screen 14 via a supply chute 12 and sieved. After sieving, powder lumps 2 are placed on sieve 1
6 and the lower end 18, and each is transported to a subsequent process. However, in the conventional sieving device as described above, the following phenomenon occurs after the material is cut out from the storage tank 8 by the cutting device 10 and before it is supplied onto the screen 14. (A) The powder lumps 2 in the storage tank 8 are cut out in a state where particle size segregation has occurred due to height fluctuations in the tank, and are supplied to the screen 14. (B) When being supplied from the cutting device 10 to the screen 14 via the supply chute 12, the supply chute 1
2 drops the powdery material 2 at the center of the screen 14, so that the layer thickness in the width direction of the screen 14 is thicker at the center than at the side edges at the screen width l and is uneven, as shown in FIG. 2A. Become. This tendency is particularly strong when the supply amount is small and when fine grain raw materials are used. (C) When the powder agglomerates are supplied onto the screen 14, the powder agglomerates 2 first collide with the supply chute 12, and at this time, there is a difference in the falling trajectory due to the difference in the particle size of the raw material, and a difference in the center as shown in FIG. 2A. The swelling causes a deviation in the particle size distribution in the width direction of the screen 14, as shown in FIG. 3A. Generally, in sieving using a screen, it is desirable for the raw material particle size distribution in the width direction on the screen to be uniform and for the raw material layer thickness to be the same from the viewpoint of sieving efficiency, but in conventional sieving equipment, these conditions are not met as described above. This was a major impediment to improving sieving efficiency. The purpose of the present invention is to solve the problems of the above-mentioned prior art and to provide a sieving device in which the particle size distribution and layer thickness distribution on the screen are uniform. The gist of the present invention is as follows.
That is, a storage tank for storing powder lumps, a cutting device for dispensing the powder lumps from the storage tank, a supply chute for relaying the powder lumps discharged from the cutting device, and a relay from the supply chute. A device for sifting powder agglomerates comprising a screen for sieving the powder agglomerates, comprising a distribution chute provided between the supply chute and the screen and capable of reciprocating in the width direction of the screen. This is a device for sifting powdery lumps. The details of the invention will be explained with reference to the illustrated embodiments.
FIG. 4 is a side view of the embodiment of the present invention, and FIG. 5 is a perspective view. This embodiment also has a storage tank 8, cutting device 10, supply chute 12, and screen 14 similar to the conventional one, but a distribution system as shown in FIG. A chute 20 is provided. The distribution chute 20 has a wide gutter shape and has a screen 14 at the tip.
It is possible to reciprocate through the rotation motor 22 and the rotation shaft 24 in the width direction. The rotation speed can be controlled in the range of 10 to 20 rpm by changing the amount of feed to the screen 14, the properties of the raw material, and the particle size.
The relative position of the distribution chute 20 is the relative position of the distribution chute 12
The falling position of the raw material from the to the distribution chute 20 is on the screen 14, and the position is such that the raw material does not fall outside the screen 14 under any circumstances.
Further, in order to prevent the powder lumps 2 from stagnation, the distributing chute 20 is preferably sloped at the tip of the gutter and equipped with a vibrating device 26. This vibration device 2
The vibration motor 28 of No. 6 can be operated either continuously or intermittently. As for control, there is a control device 32 that controls the sieving motor 30 for the sieving operation of the screen 14, the swing motor 22 of the distribution chute 20, the vibration motor 28, etc.
is provided. Furthermore, a television camera 34 is installed to monitor the sieving situation, and the raw material supply and sieving conditions can be monitored through the television monitor 36. In this embodiment, the distribution chute 20 is provided between the supply chute 12 and the screen 14, but depending on the relative positional relationship between the cutting device 10 and the screen 14, the supply chute 12 may be eliminated and the cutting Distribution chute 2 of the present invention that can be pivoted to the dispensing device 10
0 can also be communicated directly and fed to the screen 14. Next, the operation and effect of the sieving device of the present invention having the above-mentioned configuration will be explained. First, to start the work, the sieving motor 30 is driven via the control device 32 to operate the screen 14. When the signal to start driving the sieving motor 30 is fed back to the control device 32, the control device 32
drives the swing motor 22, and the tip of the distribution chute 20 swings left and right across the entire width of the screen 14. Further, at this time, the vibration motor 28 is driven as necessary to cause the distribution chute 20 to vibrate by the vibration device 26. After confirming the rotation of the distribution chute 20 on the television monitor 36, when the cutting device 10 is driven, the powder lump 2 passes through the supply chute 12 and enters the distribution chute 2.
Flows into 0. Distribution chute 20 is screen 1
4, the powder lumps 2 are uniformly supplied in the width direction of the screen 14. As the screen 14 is used to supply the powder as described above, even if particle size segregation occurs due to height fluctuations of powder agglomerates in the storage tank 8 and particle size segregation occurs during feeding from the cutter 10 to the supply chute 12, once the powder is distributed The powder agglomerates 2 are supplied to the chute 20 and a cushion is placed thereon, and then the distribution chute 20, which reciprocates in the width direction of the screen 14, distributes and supplies the material onto the screen 14, resulting in particle size segregation in the width direction of the screen 14. does not occur. Moreover, even if there is particle size segregation in the width direction of the distribution chute 20, the grain size segregation in the width direction of the screen 14 will not occur because the particles are supplied to the screen 14 by the reciprocating rotational movement. Further, the layer thickness of the powdered material 2 on the screen 14 becomes uniform in the width direction because of the supply by the rotation of the distribution chute 20. The layer thickness and particle size distribution in the width direction on the screen 14 in the present invention are shown in Fig. 2B and Fig. 3B, respectively.
However, compared to FIG. 2A and FIG. 3A, which show the layer thickness and particle size distribution by the conventional sieving device shown in FIG. It is clear that the particle size distribution is extremely uniform. Example Powder lump 2 having the particle size shown in Table 1 was used and sieved at a classification point of 5 mm. The sieving apparatus uses the embodiment of the present invention shown in Figures 4 and after and the conventional example shown in Figure 1, and compares the sieving results.
Shown in the table. Note that the above-sieve efficiency and below-sieve efficiency were determined by the following formula. Efficiency on the sieve = Weight above the classification point in the upper part of the sieve / Weight in the feeding ore exceeding the classification point Efficiency under the sieve = Weight below the classification point in the bottom part of the sieve / Weight below the classification point in the ore feed From Table 1 It is clear that in the example of the present invention, the efficiency on the sieve was improved by 10% from 85% to 95%, and the efficiency under the sieve was improved by 24% from 66% to 90%, compared to the conventional example. We were able to supply raw materials of good quality to subsequent processes. As is clear from the above embodiments, the present invention

[Table] A rotatable distribution chute is installed between the chute and the screen, and the layer thickness and particle size distribution of the powder agglomerates supplied onto the screen are made uniform, improving the sieving efficiency and improving the efficiency of subsequent processes. This has been effective in supplying high-quality raw materials.

[Brief explanation of the drawing]

Figure 1 is a process diagram showing a conventional sieving device, Figures 2 A and B are cross-sectional views showing the layer thickness in the width direction of the powder lumps on the screen, and Figures 3 A and B are the powder lumps on the screen. A diagram showing the particle size distribution in the width direction of the object, Fig. 4 is a side view showing the embodiment of the invention, Fig. 5 is a perspective view showing the embodiment of the invention, and Fig. 6 shows the distribution chute of the embodiment of the invention. FIG. 2... Powder-like material, 6... Conveyor, 8... Storage tank, 10... Cutting device, 12... Supply chute,
14...Screen, 20...Distribution shoot, 2
2...Swivel motor, 24...Swivel shaft, 26...Vibration device.

Claims (1)

[Scope of utility model registration request] a storage tank for storing powder lumps; a cutting device for discharging the powder lumps from the storage tank; a supply chute for relaying the powder lumps discharged from the cutting device; A device for sifting powder lumps comprising a screen for sieving powder lumps, comprising a distribution chute provided between the supply chute and the screen and capable of reciprocating in the width direction of the screen. A sieving device for powdery lumps, which is characterized by: