JP6233786B2 - Dry separation device - Google Patents

Description

  The present invention relates to a dry separation apparatus.

  Conventionally, a dry separation method using a difference in specific gravity of materials has been proposed in order to separate and collect materials for a mixture of two or more types of materials such as automobile shredder dust (for example, (See Patent Document 1).

  In the dry separation method, air is pumped upward from the bottom surface of a cylindrical separation tank, and density segregation is performed by flowing separation objects such as automobile shredder dust contained in the separation tank with air. For example, plastic waste having a relatively low density and metal waste having a relatively high density can be separated. Here, the flow velocity of the air flow generated in the separation tank is called “superficial velocity”, and desired separation is possible by adjusting the superficial velocity according to the separation object.

JP 2008-246393 A

  However, in the dry separation method described above, when the separation object is in the form of fine particles, even if there is a difference in density, the individual particles themselves are light in weight, and thus are easily flown by air. There was a problem that density segregation did not occur. In particular, in this case, it was not possible to find a condition for causing density segregation only by adjusting the superficial velocity.

  In view of such a current situation, the present invention has been researched and developed in order to find out the conditions under which density segregation occurs even for a fine particulate separation object, and has reached the present invention.

The dry separation device of the present invention has a bottomed cylindrical shape, a separation tank provided with a gas dispersion plate on the bottom surface, a ventilation pipe whose one end is connected to the bottom surface of the separation tank, and the ventilation pipe. It is a dry separation apparatus provided with an air supply means for pressure-feeding air and a rocking means for rocking the separation tank .

In particular, the minimum superficial velocity at which the separation object accommodated in the separation tank becomes fluidized by the air sent to the separation tank by the air supply means is the minimum fluidization speed, and the separation object is the first powder. The powder and the second powder are mixed in equal amounts, and the bulk density of the second powder is 1.67 times the bulk density of the first powder.

Further, the swinging means is two swinging devices, which cause vibrations in the vertical direction by canceling horizontal vibrations to each other, and the swinging device has an excitation force of 1.5 kN and a frequency of 60 Hz. The first powder is segregated in the upper layer side 30% of the separation tank by setting the superficial velocity to the minimum fluidization speed while swinging the separation tank.

  According to the present invention, it is possible to separate an object to be separated, which cannot be separated by a conventional dry separation apparatus having no rocking means.

It is a schematic diagram of the dry separation apparatus of 1st Example. It is a graph of the bulk volume mixing ratio and bulk density of the mixed powder of glass beads and unibeads. It is a graph of the process result by the dry-type separation apparatus in each superficial velocity without vibration. It is a graph of the processing result by the dry-type separation apparatus in each superficial velocity which made the vibration conditions excitation force 1.5kN and frequency 60Hz. It is a graph of the processing result by the dry-type separation apparatus in each superficial velocity which made the vibration conditions excitation force 1.5kN and frequency 60Hz. It is a graph of a separation grade in which the horizontal axis is the superficial velocity ratio U ₀ / U _mf and the vertical axis is the separation grade. It is a graph of the process result by the dry-type separation apparatus which made the superficial velocity 0 cm / s and made each vibration condition. It is a graph of the processing result by the dry-type separator which made the superficial velocity the minimum fluidization speed, and made each vibration condition. It is a graph of the processing result by the dry-type separator which made the superficial velocity the minimum fluidization speed, and made each vibration condition. It is a graph of the processing result by the dry-type separator which made the superficial velocity the minimum fluidization speed, and made each vibration condition. It is a graph of the separation grade with the horizontal axis as the vibration strength and the vertical axis as the separation grade. It is a schematic diagram of the dry separation apparatus of 2nd Example. It is a graph of the measurement result of the minimum fluidization speed in each knock condition. It is a graph of the measurement result of the minimum fluidization speed in each knock condition. It is a graph of the processing result by the dry-type separation apparatus in each superficial velocity which made the knock conditions pressure 0.5MPa and knock frequency 2.0Hz. It is a graph of the processing result by the dry-type separator which made the superficial velocity the minimum fluidization speed, and made each pressure condition. It is a graph of the process result by the dry-type separation apparatus which made each superficial velocity the minimum fluidization speed, and made each knock frequency condition.

  The dry separation device of the present invention has a bottomed cylindrical shape, a separation tank provided with a gas dispersion plate on the bottom surface, a ventilation pipe whose one end is connected to the bottom surface of the separation tank, and the ventilation pipe. A dry separation apparatus including an air supply means for pressure-feeding air, and provided with a swinging means for swinging the separation tank.

  FIG. 1 is a schematic diagram of the dry separation apparatus of the first embodiment. The dry separation apparatus of the first embodiment has a bottomed cylindrical shape, and a separation tank 11 provided with a gas dispersion plate on the bottom surface. A dry separation apparatus comprising a ventilation pipe 21 having one end connected to the bottom surface of the separation tank 11 and an air supply means 30 for pressure-feeding air into the ventilation pipe 21, and the separation tank 11 is swung. The swinging means 40 is provided.

  The air supply means 30 is capable of generating an air flow at a predetermined superficial velocity in the separation tank 11 by sequentially connecting a compressor 31, a regulator 32, a mass flow controller 33, and a three-way cock 34 from the upstream side. Yes.

  The separation tank 11 is provided above the base 12 via the swinging means 40. The swing means 40 includes a swing device 41 for generating vibration, a frame 42 that supports the swing device 41 and connects the separation tank 11 and the base 12, and the frame 42 and the base 12 And a rubber cushioning material 43 that absorbs vibrations between them. In this embodiment, two oscillating devices 41 are provided, and the oscillating devices 41 are respectively mounted horizontally, and the vertical vibrations are generated by mutually canceling the horizontal vibrations. Specifically, as the rocking device 41, KEE-1.5-4 3PHASE manufactured by Eurus Techno Co., Ltd. was used. The swing device 41 can be operated with an excitation force in the range of 0 to 1.5 kN by adjusting the unbalance weight.

  In this embodiment, the separation tank 11 is an acrylic cylindrical tube having an inner diameter of 103 mm, a height of 400 mm, and a thickness of 5 mm, and a gas dispersion plate 11a is attached to the bottom of the separation tank 11. The gas dispersion plate 11a of the present embodiment is made of a porous material, specifically, a filter material, but allows air to flow into the separation tank 11, while preventing leakage of the contents in the separation tank 11. If so, the gas dispersion plate 11a may be configured in any way. In particular, it is desirable that the gas dispersion plate 11a is dispersed so as to generate ascending air flow as uniform as possible in the cylindrical separation tank 11, and can be pumped into the separation tank 11. In the present embodiment, an outer edge portion 11b for mounting on the frame 42 is provided on the outer peripheral edge of the gas dispersion plate 11a, and the separation tank 11 is mounted on the frame 42 via the outer edge portion 11b. In FIG. 1, reference numeral 11 c denotes a connection guide for connecting the ventilation pipe 21 and the separation tank 11.

  In this embodiment, specifically, the gas dispersion plate 11a is configured by sandwiching a punching metal of SUS304 with a filter cloth. Specifically, the punching metal was a flat metal having a thickness of 2.0 mm, a hole diameter of φ2.5 mm, a hole pitch of 5.0 mm, a hole area ratio of 22.7%, and a punching metal of 60 degrees zigzag type.

  In the dry separation apparatus configured as described above, the state of vibration by the rocking means 40 was confirmed. Specifically, a mark as a mark was provided on the outer surface of the separation tank 11, and the mark was photographed with a high-speed camera while driving the swinging device 41 under various conditions, and the frequency and amplitude of vibration were measured. . Based on this result, the drive condition of the rocking device 41 was specified. In the swinging means 40 of the present embodiment, vertical vibrations could be generated in the separation tank 11 as expected.

In the present embodiment, the separation object contained in the separation tank 11 is a mixed powder of two components of glass beads and unibeads. The glass beads and unibeads were each screened with a JIS test sieve (JIS Z 8801), and the particle size was adjusted to 180 to 212 μm .

In the present embodiment, the bulk density is used for the evaluation of the separation of the mixed powder of glass beads and unibeads. In particular, in this embodiment, an appropriate amount of sample powder is put into a volumetric flask, the volume is set to V [cm ³ ] by reading the scale of the volumetric flask after tapping the volumetric flask 5 times and filling the powder. Then, measure the mass m [g] with an electronic balance,
ρ = m / V
Thus, the bulk density ρ was calculated.

Incidentally, the bulk density of the glass beads is 1.50 g / cm ^3, a bulk density of Yunibizu is a 2.51 g / cm ^3, who Yunibizu is Mocha bulk density was about 1.67 times greater than the glass beads. Moreover, the bulk density of the mixed powder obtained by mixing equal amounts of glass beads and unibeads is 2.05 g / cm ^{3. As} shown in FIG. 2, the bulk density of the unibeads and glass beads depends on the bulk density of the mixed powder. It was confirmed that the volume mixing ratio could be specified. In FIG. 2, the horizontal axis represents the bulk volume mixing ratio of unibeads.

  In the usual dry separation method, it is impossible to separate the mixed powder of glass beads and unibeads having such a small density difference. As a precaution, in the above-described dry separation apparatus of the present embodiment, it was verified whether the mixed powder of glass beads and unibeads can be separated when the separation tank 11 is not vibrated.

  First, a mixed powder in which equal amounts of glass beads and unibeads are mixed is put into the separation tank 11 so that the height is 105 mm, and air is pumped to the separation tank 11 by the air feeding means 30 to make glass beads or unibeads. Urged segregation. After the air was pumped into the separation tank 11 for a predetermined time, the pumping of air was stopped and the occurrence of segregation was confirmed. Specifically, the occurrence of segregation can be confirmed by taking out the mixed powder for a thickness of 15 mm between the height of 90 to 105 mm of the separation tank 11 from the mixed powder in the separation tank 11 and The bulk density was measured as one layer, and then the mixed powder of 10 mm in thickness between 80 to 90 mm in height of the separation tank 11 was taken out, and the bulk density was measured as the second layer. The mixed powder of 10 mm in length was sequentially taken out, the bulk density was measured, the bulk density up to the 10th layer was measured, and the change in bulk density was examined.

  In the dry separation apparatus, it is necessary that the separation object accommodated in the separation tank 11 be in a fluid state by the air sent to the separation tank 11 by the air feeding means 30. Usually, the minimum superficial velocity at which this fluidized state is reached is called the minimum fluidization velocity. In this embodiment, the minimum fluidization speed is 3.4 cm / s, and this is used as a reference. The air supply time by the air supply means 30 was 600 seconds.

  Specifically, the minimum fluidization speed was determined as follows. First, in the separation tank 11, a differential pressure gauge probe is provided in advance, the separation object is stored in the separation tank 11, and air is supplied from the air feeding means 30 to the separation tank 11, while the particle layer of the separation object The pressure loss is detected with a differential pressure gauge. When the pressure loss is measured while increasing the superficial velocity, the pressure loss does not change after the pressure loss is balanced with the weight of the particle layer of the separation object. The minimum superficial velocity that balances this pressure loss with the dead weight of the particle layer of the separation object is set as the minimum fluidization velocity.

  FIG. 3 shows the result when the separation tank 11 is not vibrated and the superficial velocity of the air sent to the separation tank 11 is adjusted by the air supply means 30. The upper left column has a superficial velocity of 0 cm / In the case of s, the left middle stage is when the superficial velocity is half of the minimum fluidization speed, the lower left side is when the superficial velocity is the minimum fluidization speed, and the upper right side is when the superficial velocity is the minimum fluidization. This is the case of 1.5 times the speed, and the middle stage on the right is when the superficial velocity is twice the minimum fluidization speed. Each horizontal axis is the bulk volume mixing ratio of the unibeads identified from the measured bulk density. As apparent from FIG. 3, when the separation tank 11 was not vibrated, no density segregation occurred in the mixed powder of glass beads and unibeads.

  On the other hand, FIG. 4 and FIG. 5 show the results when the separation tank 11 is vibrated by the swinging means 40 under the conditions of an excitation force of 1.5 kN and a frequency of 60 Hz. The upper left column in Fig. 4 is when the superficial velocity is 0 cm / s, and the second from the top left is when the superficial velocity is 0.125 times the minimum fluidization rate, and the third from the top left. Is the case where the superficial velocity is 0.25 times the minimum fluidization speed, the fourth stage from the top on the left is the case where the superficial velocity is 0.5 times the minimum fluidization speed, and the topmost right is the lowest superficial velocity. This is the case when the fluidization speed is 0.75 times, the second stage from the top right is the case where the superficial velocity is 0.875 times the minimum fluidization speed, and the third stage from the top right is the minimum superficialization. In the case of velocity, the fourth stage from the top right is when the superficial velocity is 1.125 times the minimum fluidization velocity. The upper stage of FIG. 5 shows the case where the superficial velocity is 1.25 times the minimum fluidization speed, the middle stage shows the case where the superficial velocity is 1.5 times the minimum fluidization speed, and the lower stage shows the case where the superficial velocity is the minimum fluidization. This is the case of twice the speed. Each horizontal axis is the bulk volume mixing ratio of the unibeads identified from the measured bulk density.

  In the case where the superficial velocity of the uppermost stage on the left side of FIG. 4 is 0 cm / s, while the unibeads having a higher specific gravity than the glass beads are levitated, the glass beads having a lower specific gravity have settled. I think this is a unique phenomenon in this experimental system.

Figure 6 is a graph summarizing the results of FIGS. 3-5, the horizontal axis represents the minimum fluidization velocity U is the ratio of the superficial velocity U ₀ for _mf superficial velocity ratio U ₀ / U _mf, the vertical axis It was evaluated as a separation grade. As is apparent from FIG. 6, density segregation occurs when the separation tank 11 is vibrated with the superficial velocity of the separation tank 11 set to 0.75 to 1.25 times the minimum fluidization speed, and normally, fine particles that do not cause density segregation. Density segregation can also be caused to the separation object.

  Next, confirmation of the relevance of the vibration conditions of the separation tank 11 to density segregation was performed in the same manner as in the above experiment.

  Figure 7 shows the case where the superficial velocity is 0 cm / s and the separation tank 11 is vibrated with an excitation force of 1.5 kN. The upper left side shows the case where the vibration frequency is 15 Hz, and the left middle part shows the vibration frequency. In the case of 27.5 Hz, the lower left side is when the vibration frequency is 35 Hz, the upper right side is when the vibration frequency is 50 Hz, and the middle right side is when the vibration frequency is 60 Hz. Each horizontal axis is the bulk volume mixing ratio of the unibeads identified from the measured bulk density.

  As mentioned above, when the separation tank 11 is vibrated under the conditions of an excitation force of 1.5 kN and a frequency of 60 Hz with a superficial velocity of 0 cm / s, this is a unique phenomenon in this experimental system. it is obvious. Further, as apparent from FIG. 7, density segregation does not occur in the mixed powder only by vibration.

  Next, FIGS. 8 to 10 show the results in the case where the superficial velocity is set to the minimum fluidization velocity and the vibration condition by the rocking means 40 is changed in various ways. The upper left side of Fig. 8 is for the case where the excitation force is 0.375kN and the frequency is 15Hz, the second step from the upper left is for the case where the excitation force is 0.75kN and the frequency is 15Hz, and the third step from the upper left is The case where the vibration force is 1.125kN and the frequency is 15Hz, the fourth stage from the upper left is the case where the excitation force is 1.5kN and the frequency is 15Hz, and the upper right part is the case where the excitation force is 0.375kN and the frequency is 27.5Hz. The second row from the top on the right is for a vibration force of 0.75 kN and a frequency of 27.5 Hz, and the third row from the top on the right is for a vibration force of 1.125 kN and a frequency of 27.5 Hz. The stage is when the excitation force is 1.5 kN and the frequency is 27.5 Hz. In addition, the upper left side of FIG. 9 is for the case where the excitation force is 0.375 kN and the frequency is 35 Hz, and the second stage from the upper left is the case where the excitation force is 0.75 kN and the frequency is 35 Hz. Is the case of excitation force 1.125kN, frequency 35Hz, the fourth stage from the upper left is the case of excitation force 1.5kN, frequency 35Hz, the upper right is the case of excitation force 1.5kN, frequency 40Hz Yes, the second stage from the top right is for a vibration force of 1.5 kN and a frequency of 45 Hz, and the third stage from the top right is for a vibration force of 1.5 kN and a frequency of 50 Hz. The eyes are when the excitation force is 1.5 kN and the frequency is 55 Hz. In addition, the upper left side of FIG. 10 shows the case where the excitation force is 0.375 kN and the frequency 60 Hz, the lower left side is the case where the excitation force is 0.75 kN and the frequency 60 Hz, and the upper right side shows the case where the excitation force is 1.125 kN and the frequency 60 Hz. The lower right column shows the case where the excitation force is 1.5 kN and the frequency is 60 Hz. Each horizontal axis is the bulk volume mixing ratio of the unibeads identified from the measured bulk density.

  When the frequency is 15 Hz, as is apparent from FIG. 8, slight segregation is observed at the uppermost layer and the lowermost layer. When the frequency is 27.5 Hz and 35 Hz, as shown in FIGS. 8 and 9, the bulk volume mixing ratio of the uni-beads gradually increases from the upper layer to the lower layer, and is particularly noticeable in the uppermost layer and the lowermost layer. Segregation has occurred. Such a segregation state is referred to as “inclined segregation”.

  When the frequency was 60 Hz, it was confirmed that significant segregation occurred on the upper layer side as shown in FIG. In addition, while the excitation force is as small as 0.375 to 0.75 kN, inclined segregation is observed, but when the excitation force is greater than 1.125 kN, the bulk of the uni-beads is lowered from the central portion of the separation tank 11 in the vertical direction. There was a phenomenon that the volume mixing ratio was almost constant. Further, as shown on the right side of FIG. 9, even when the frequencies are 40 Hz, 45 Hz, 50 Hz, and 55 Hz, the bulk volume mixing ratio of the unibeads is substantially constant from the central portion in the vertical direction of the separation tank 11 to the lower side. The phenomenon was seen. In this way, the segregation state in which the bulk volume mixing ratio is substantially constant above the certain height of the separation tank 11 while the remarkable segregation occurs above the certain height of the separation tank 11 is referred to as “step-like segregation”. ".

From the results of FIGS. 7 to 10, since the vibration frequency and amplitude are likely to be correlated with the segregation state, the vibration amplitude by the rocking means 40 is a, the vibration frequency is f, and the gravitational acceleration is g
G = a · (2π · f) ² / g
Was introduced, and the results of FIGS. 7 to 10 were analyzed.

  In FIG. 11, the horizontal axis is the vibration strength G and the vertical axis is the separation grade. The symbol in the graph indicates no segregation, the symbol Δ indicates inclined segregation, and the symbol ○ indicates step segregation. Show.

  From FIG. 11, it can be seen that if the vibration intensity G is 3.0 or more, the separation efficiency of the separation object can be improved by the occurrence of step-like segregation.

  In the embodiment described above, the separation tank 11 is vibrated in the vertical direction. However, by adjusting the driving conditions of the rocking device 41, not only the separation tank 11 is vibrated in the vertical direction but also the vibration of the horizontal component. It is also possible to cause a vibration in the oblique direction as a whole by applying the vibration of the horizontal component. In particular, the direction of the oblique direction may not be constant, but may be variable to cause a state in which the vibration direction rotates.

  FIG. 12 is a schematic diagram of the dry separation device of the second embodiment. The dry separation device of the second embodiment is a dry separation device using an air knocker 51 as a swinging means for swinging the separation tank 11. is there. Except for the swinging means, it is the same as the dry separation apparatus of the first embodiment, and in the following, the same reference numerals are used for the same structures as the dry separation apparatus of the first embodiment, and the detailed description is omitted.

  The dry separation apparatus of the second embodiment also has a separation tank 11 provided with a gas dispersion plate 11a on the bottom surface, a ventilation pipe 21 having one end connected to the bottom surface of the separation tank 11, and air in the ventilation pipe 21. Is a dry separation device including an air supply means 30 for pressure-feeding.

  The air supply means 30 is capable of generating an air flow at a predetermined superficial velocity in the separation tank 11 by sequentially connecting a compressor 31, a regulator 32, a mass flow controller 33, and a three-way cock 34 from the upstream side. Yes. In the first embodiment, POD-7.5MB5 / 6 manufactured by Hitachi, Ltd. is used as the compressor 31, but POD-3.7GXA6 manufactured by Hitachi, Ltd. is used in the second embodiment.

  At the lower end of the separation tank 11, a mounting flange 11d for mounting on the base 12 is provided, and by mounting on the support base 12a provided on the base 12 via this mounting flange 11d, the air knocker 51 The swingable separation tank 11 can be firmly supported.

  The air knocker 51 is attached to a side surface of a cylindrical connection guide 11c that connects the ventilation pipe 21 and the separation tank 11, and applies impact by hitting the connection guide 11c. Although not shown, the air knocker 51 is connected to a pressure pump that sends compressed air via an appropriate regulator and control box, and the regulator and control box are adjusted to increase the impact force. The frequency of shock occurrence is adjusted. As the air knocker 51, SK-40 of Seishin Corporation was used, and SE-710 of Seishin Corporation was used as the control box.

  As in the first embodiment, the separation tank 11 is an acrylic cylindrical tube having an inner diameter of 103 mm, a height of 400 mm, and a thickness of 5 mm, and a gas dispersion plate 11a is attached to the bottom of the separation tank 11. Also in this embodiment, the gas dispersion plate 11a is configured by sandwiching a punching metal of SUS304 with a filter cloth. Specifically, the punching metal was a flat metal having a thickness of 2.0 mm, a hole diameter of φ2.5 mm, a hole pitch of 5.0 mm, a hole area ratio of 22.7%, and a punching metal of 60 degrees zigzag type.

  In this embodiment, the separation object contained in the separation tank 11 is also a mixed powder of two components of glass beads and unibeads, and the above bulk density is used for the evaluation of the separation of the mixed powder of glass beads and unibeads. It was.

  First, when the minimum fluidization speed in the state where the air knocker 51 in this example is not operated is measured, the glass beads are 3.9 cm / s, the uni beads are 7.0 cm / s, and the mixed powder of the glass beads and uni beads. Then it was 5.2cm / s.

  Next, the minimum fluidization speed with the air knocker 51 activated was measured. Here, as a knock condition, the pressure was set to 0.5 MPa by a regulator, the ON time as an impact time was set to 0.1 s by the control box, and the OFF time as an interval time was set to 0.4 s. The s and unibeads were 4.9 cm / s, and the mixed powder of glass beads and unibeads was 3.8 cm / s.

  Next, the effect of knock conditions on the minimum fluidization rate was confirmed. Note that when only the ON time and OFF time were adjusted with the same knocking frequency, there was no change in the minimum fluidization speed, so the ON time was fixed at 0.1 s and the knocking frequency was changed by varying the OFF time. Changed. Here, the knock frequency is expressed using [Hz] as the number of knocks per second.

  FIG. 13 shows the measurement results of the minimum fluidization speed when the knock frequency is 2.0 Hz and the pressure is 0.3, 0.5, 0.7 MPa by a regulator. In FIG. 13, □ marks indicate glass beads, ◯ marks indicate uni-beads, and Δ marks indicate mixed powders of glass beads and uni-beads. Similarly, FIG. 14 shows the measurement results of the combined minimum fluidization speed with the pressure set to 0.5 MPa by the regulator and the knock frequency set to 8 conditions of 0.2 to 5.0 Hz. Also in FIG. 14, □ marks indicate glass beads, ◯ marks indicate uni-beads, and Δ marks indicate mixed powders of glass beads and uni-beads.

From these measurement results, the separation state of the mixed powder of glass beads and unibeads by the dry separation device when the pressure is 0.5 MPa by the regulator, the knock frequency is 2.0 Hz, and the superficial velocity is varied is shown in FIG. Show. Superficial velocity, based on the minimum fluidization velocity u _mf, 0 times the minimum fluidization velocity u _mf (no wind), 0.5-fold, 0.75-fold, 0.875-fold, 1.0-fold, 1.125-fold, 1.25-fold, 1.5-fold, 1.75 Double and 2.0 times were measured. The fluidization time was 600 seconds.

The upper left side of FIG. 15 shows the case where the minimum fluidization speed u _mf is 0 times, and the second stage from the upper left side shows the case where the minimum fluidization speed u _mf is 0.5 times, and the third stage from the upper left side. Is the case of 0.75 times the minimum fluidization speed u _mf, the fourth stage from the top left is 0.875 times the minimum fluidization speed u _mf , and the fifth stage from the top left is the minimum fluidization speed u _This is the case of 1.0 times _mf , the upper right side is the case of 1.125 times the minimum fluidization speed u _mf , and the second stage from the upper right is the case of 1.25 times the minimum fluidization speed u _mf , the right side The third row from the top is for 1.5 times the minimum fluidization rate u _mf , and the fourth row from the top on the right is 1.75 times the minimum fluidization velocity u _mf , and the fifth row from the top on the right Is the case of 2.0 times the minimum fluidization speed u _mf . Each horizontal axis is the bulk volume mixing ratio of the unibeads identified from the measured bulk density. From FIG. 15, it was confirmed that uneven accumulation was likely to occur near the minimum fluidization speed u _mf .

From the above results, in a state where the mixed powder of glass beads and unibeads is fluidized at the minimum fluidization speed u _mf , the knock condition, that is, the regulator pressure is 0.3 to 0.7 MPa, the knock frequency is 0.5 to 5.0 Hz. Differently, the separation situation of the mixed powder of glass beads and unibeads by the dry separation apparatus under each condition was confirmed. The fluidization time was 600 seconds.

Here, in order to quantify the progress of density segregation, the degree of segregation E was defined by the following equation.
The symbol V ₅₀ in the formula indicates the bulk volume mixing ratio V _{UB of} unibeads = 50 vol%, and the symbol V _i indicates the bulk volume mixing ratio V _UB of the uni-beads in the i-th layer. This shows the progress of density segregation at 0 to 100%. E = 0% indicates that no density segregation phenomenon occurs, and E = 100% indicates that the density segregation phenomenon is remarkable. Show.

  FIG. 16 shows a graph showing the tendency of the segregation degree E with respect to the pressure. As shown in FIG. 16, it is understood that the regulator pressure is preferably about 0.4 MPa. Moreover, the graph which shows the tendency of the segregation degree E with respect to knock frequency in FIG. 17 is shown. As shown in FIG. 17, it is desirable that the knock frequency is large as long as it is large. From the above, as preferable knock conditions, it is desirable that the regulator pressure is 0.4 MPa and the knock frequency is 5.0 Hz.

11 Separation tank
11a Gas dispersion plate
11b Outer edge
11c Connection guide
12 base
21 Ventilation piping
30 Air supply
31 Compressor
32 Regulator
33 Mass flow controller
34 Three-way cock
40 Oscillating means
41 Oscillator
42 frames
43 cushioning material

Claims (1)

A separation tank having a bottomed cylindrical shape and provided with a gas dispersion plate on the bottom surface;
A ventilation pipe having one end connected to the bottom of the separation tank;
An air supply means for pumping air into the ventilation pipe ;
In a dry separation apparatus comprising rocking means for rocking the separation tank ,
The separation object accommodated in the separation tank is set to a minimum fluidization speed, which is the minimum superficial velocity at which the separation object enters a fluidized state by the air sent to the separation tank by the air feeding means,
The separation object is a mixed powder in which an equal amount of the first powder and the second powder are mixed,
The bulk density of the second powder is 1.67 times the bulk density of the first powder;
The oscillating means is two oscillating devices, and generates vibrations in the vertical direction by canceling horizontal vibrations together.
While the separation tank is swung with the rocking device having an excitation force of 1.5 kN and a frequency of 60 Hz , the superficial velocity is set to the minimum fluidization speed , so that the first 30% of the upper side of the separation tank is the first. Dry separation device that segregates powder .