JP6064640B2 - Solid-liquid separation method and apparatus - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a solid-liquid separation method and apparatus for separating solid particles contained in a liquid, and in particular, solid-liquid separation that is effective for separating solid particles that have no density difference from a liquid or are small. It relates to a method and a device.

  There are a reverse osmosis membrane method and a forward osmosis membrane method as a method for desalinating seawater or desalting water associated with shale gas. When carrying out such a reverse osmosis membrane method or forward osmosis membrane method, it is possible to separate and remove solid particles such as sand, clay and colloid contained in water as a pretreatment before the membrane treatment. Desired. Furthermore, in the case of the desalination treatment of the seawater, it is desired that solid particles such as algae and other microorganisms, dead bodies and metabolites contained in the water are separated and removed by pretreatment.

  In addition, when algae, cells, and other microorganisms are cultured to produce pharmaceuticals, fuels, and other useful substances, the cultured microorganisms and cells are submerged in water ( A pretreatment for separation from the culture medium) is required.

  Furthermore, for the purpose of purifying lakes and marshes, microorganisms such as algae are separated from water.

  When solid-liquid separation is performed, a solid-liquid separation technique using a density difference between solid particles to be separated and a liquid serving as a dispersion medium for the solid particles is widely and generally performed. That is, when the density of solid particles is larger than the density of liquid, sedimentation separation is performed. On the other hand, when the density of the solid particles is smaller than the density of the liquid, levitation separation is performed. In addition, when the density difference between the solid particles and the liquid is relatively small, centrifugal separation that promotes sedimentation and floating of the solid particles based on the same solid-liquid density difference as described above using centrifugal force is performed. Widely done.

  However, the sand, clay, colloid, algae, cells and other microorganisms, and dead bodies and metabolites thereof have a small particle size, and further, there is no density difference with water or the density difference is a minute particle. In some cases, it is difficult to separate such solid particles from a liquid by conventional general solid-liquid separation techniques such as sedimentation, centrifugation, and flotation.

  By the way, a fine particle continuous concentrating device that concentrates fine particles in a liquid using ultrasonic waves has been conventionally proposed. This is because the ultrasonic vibrator for generating a standing wave in the pipe is provided on both side walls of the pipe through which the fluid containing the fine particles flows. It concentrates on the node of the standing wave of the ultrasonic wave generated from the sonic transducer and the position of the abdomen. Furthermore, a suction thin tube is arranged downstream of the portion where the fine particles are concentrated in the tube so as to selectively suck the fluid containing the concentrated fine particles (for example, patents). Reference 1).

  A non-contact manipulation method using ultrasonic waves has been proposed in the past. This is to generate a standing wave by the ultrasonic wave radiated from the ultrasonic vibrator between the ultrasonic vibrator and the reflection plate installed in parallel in the water tank, and capture a minute object (particle) at the node. Let Thereafter, the minute object captured in the node is moved in the propagation direction of the sound wave between the ultrasonic transducer and the reflecting plate by changing the frequency of the ultrasonic wave (for example, Patent Document 2).

  However, the non-contact manipulation method is difficult to apply to a continuous solid-liquid separation process for a liquid containing particles.

  Further, a continuous separation method for suspended particles using acoustic radiation force and electrostatic force has been proposed. This is because small particles of suspended particles flowing in the flow channel are guided to one side wall of the flow channel by electrostatic force, and further, the ultrasonic wave is placed between the transducer and the reflector so that the acoustic radiation force works. By generating a wave so as to move the position of the node by scanning the frequency, the large-diameter particles of the suspended particles are guided to the other side wall of the flow path (for example, Patent Document 3). reference).

  However, the above-mentioned continuous separation method of suspended particles is for sorting suspended particulates in a liquid according to the particle size, and does not perform solid-liquid separation. Force and electrostatic force must be used together.

Japanese Patent Laid-Open No. 9-122480 Japanese Patent Application Laid-Open No. 11-104979 JP 2007-229557 A

  However, the fine particle continuous concentration apparatus disclosed in Patent Document 1 concentrates particles in a fluid in a tube only with standing waves generated at one place in the longitudinal direction of the tube. Furthermore, since the particles concentrated by the standing wave are selectively sucked using a single thin tube disposed downstream of the standing wave generation location, the standing wave generated in the tube Needs to be a standing wave with only one node or antinode for trapping particles in the fluid.

  Therefore, when the cross-sectional area of the pipe is large, the distance from the position near the outer periphery of the cross-section of the flow path in the pipe to the single node or antinode for capturing the standing wave particles becomes large. It is difficult to capture particles that travel toward the location of the standing wave through the position near the outer periphery of the particle by moving it to the node or antinode of the standing wave.

  In addition, since the standing wave is generated only at one position in the longitudinal direction of the tube, the particles that have passed through the standing wave generation position without being completely captured by the standing wave node or belly are described below. After that, there is no means to capture and separate. Therefore, with the thing shown in the said patent document 1, it is also difficult to raise the flow velocity of the fluid in a pipe | tube.

  Therefore, it is difficult for the technique disclosed in Patent Document 1 to efficiently carry out continuous solid-liquid separation treatment for a large amount of fluid, such as the reverse osmosis membrane method and forward osmosis as described above. As a pretreatment for desalination of seawater and shale gas associated water by membrane method, solid particles such as sand, clay, colloid, algae and other microorganisms and their dead bodies and metabolites contained in the water are separated from the liquid. It is difficult to apply the solid-liquid separation process for the separation and the solid-liquid separation process for separating the algae, cells and microorganisms from the water (in the culture solution).

  Therefore, the present invention makes it possible to eliminate the above-mentioned conventional problems, and efficiently performs solid-liquid separation even for fine solid particles that have no density difference from the liquid that serves as a dispersion medium for the solid particles. In addition, an object of the present invention is to provide a solid-liquid separation method and apparatus effective for continuous processing.

In order to solve the above-mentioned problem, the present invention comprises, corresponding to claim 1, a flow path for circulating a stock solution in which particles are dispersed, and the flow path is provided in the flow path by an ultrasonic wave generating element. by generating still standing waves positions of the nodes is stationary in the still standing acoustic wave generating means for forming a particle group by agglomerating to capture the particles in the section of the stationary standing acoustic wave is provided, the flow A node on the downstream side of the installation location of the stationary standing sound wave generating means in the path from the other flow path wall side facing the inside of the flow path from another ultrasonic wave generating element to the other flow path wall side. The moving standing sound wave that periodically displaces the position of the stationary standing sound wave is generated, and the aggregated particles captured by the stationary standing sound wave node are moved to the other channel by the displacement of the moving standing sound wave node. only set the moving standing wave generating means for concentrating on the wall side, further, the moving standing wave generated manually in the passage Downstream position than, a solid-liquid separator having a constitution comprising a concentrated particle outlet for taking out the particles that are concentrated in the flow path wall side of the other side in the moving standing wave.

Furthermore, in response to claim 2, in the configuration of the first aspect, the mobile standing sound wave generator, the position of the antinodes of the moving standing waves to be generated in the mobile standing sound wave generator, the other side The frequency of the moving standing sound wave is set so as not to coincide with the node of the stationary standing sound wave generated by the stationary standing sound wave generating means with reference to the flow path wall .

Further, in accordance with claim 3, when the stock solution in which the particles are dispersed is circulated through the flow path, a stationary standing sound wave with the node position stationary is applied to the stock solution in the flow path, The particles in the stock solution are trapped and aggregated in the stationary standing sound wave nodes, and then the nodes on one side opposite to each other are placed in the group of particles captured and aggregated in the stationary standing sound wave nodes. A moving standing sound wave that is periodically displaced from the channel wall side to the other channel wall side is applied to cause the particle group to move to the other side of the channel along with the displacement of the node of the moving standing sound wave. The solid-liquid separation method is such that the particles are concentrated on the channel wall side , and then the particle group concentrated by the moving standing sound wave is taken out.

According to the solid-liquid separation method and apparatus of the present invention, the following excellent effects are exhibited.
(1) The particles contained in the stock solution can be continuously subjected to solid-liquid separation treatment, and no solid-liquid density difference is required during the solid-liquid separation treatment. Solid-liquid separation can be performed efficiently even for particles having no density difference or a minute density difference. As a result, the solid-liquid separation treatment is performed as a pre-treatment for the desalination treatment of seawater or shale gas-associated water by the reverse osmosis membrane method or the forward osmosis membrane method, so that solid particles such as sand, clay and colloid contained in water Furthermore, it is suitable for a process for separating and removing solid particles such as algae and other microorganisms, dead bodies and metabolites thereof, or a process for separating algae, cells and microorganisms from water (in the culture solution). can do.
(2) As the stationary standing sound wave and the moving standing sound wave, one that captures the particles at a plurality of nodes can be used. Furthermore, in the flow path, the stationary standing sound wave generation point and the moving standing sound wave generation point are provided in multiple stages from the upstream side, so there are particles that cannot be captured by the stationary standing sound wave node. Even so, the particles can be trapped in a moving standing acoustic wave node and concentrated for separation. For this reason, it is possible to increase the flow rate of the stock solution in the flow path.

It is a cutting | disconnection schematic side view which shows one Embodiment of the solid-liquid separation method and apparatus of this invention. It is a figure which shows an example of the time change of the frequency of the movement standing sound wave generated by the movement standing sound wave generation means of the solid-liquid separator of FIG. FIG. 3 shows an outline of a waveform of a moving standing sound wave generated by the moving standing sound wave generating means of the solid-liquid separation device of FIG. 1, and (a), (b), (c), and (d) are step 1 of FIG. 2 (e) is a diagram showing waveforms at the time when the frequency of the moving standing sound wave is returned to the initial frequency in step 1 after step 4 in FIG. is there. It is a cutting | disconnection schematic side view which shows the other form of implementation of this invention. It is a figure which shows an example of the time change of the frequency of the movement standing sound wave generated by the movement standing sound wave generation means of the solid-liquid separator of FIG. FIG. 5 shows an outline of a waveform of a moving standing sound wave generated by the moving standing sound wave generating means of the solid-liquid separation device of FIG. 4, and (a), (b), (c), and (d) are step 1 of FIG. 2 (e) is a diagram showing waveforms at the time when the frequency of the moving standing sound wave is returned to the initial frequency in Step 1 after Step 4 in FIG. is there.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

  FIGS. 1 to 3 (a), (b), (c), (d), and (e) show an embodiment of the solid-liquid separation method and apparatus of the present invention.

  That is, the solid-liquid separation device of the present invention is indicated by reference numeral 1 in FIG. 1 and includes a flow path 4 for flowing a stock solution 2 in which particles 3 are dispersed in a liquid serving as a dispersion medium.

  A stationary standing sound wave generating means 5 and moving standing sound wave generating means 6A, 6B are provided in the middle of the flow path 4 in order from the upstream side.

  Further, a concentrated particle take-out port 7 for taking out the concentrated particles 3 is provided at the downstream position of the moving standing sound wave generating means 6B installed on the most downstream side in the flow path 4.

  More specifically, the channel 4 has, for example, a rectangular cross section so as to include at least a pair of channel walls 8a and 8b facing each other.

  The stationary standing sound wave generating means 5 includes an ultrasonic wave generating element 9 such as a piezoelectric element (piezo element) and a control device 10 connected to the ultrasonic wave generating element 9.

  The ultrasonic wave generating element 9 is attached to the outer surface of one channel wall 8a of the pair of channel walls 8a and 8b facing the channel 4.

  The ultrasonic wave generating element 9 may be a ceramic type, a crystal type, a resin, or the like as long as it generates an inverse piezoelectric phenomenon and can oscillate an ultrasonic wave having a desired wavelength to be described later in the flow path 4. Any kind of element known as a piezoelectric element, such as a resin system or a resin-ceramic composite system, may be used.

The control device 10 applies a voltage to the ultrasonic wave generating element 9 to generate ultrasonic vibration based on the reverse piezoelectric phenomenon, and controls the frequency of the ultrasonic vibration. The distance (hereinafter referred to as the tube diameter) d between the one and the other flow path walls 8a and 8b from the sonic wave generating element 9 into the stock solution 2 in the flow path 4 is a natural number, preferably 2 or more. An ultrasonic wave whose dimension divided by the natural number corresponds to a half wavelength (1/2 of the wavelength λ _s ) can be emitted.

  In the stationary standing sound wave generating means 5 configured as described above, the ultrasonic wave of the predetermined wavelength is caused to flow through the flow path 4 through the one flow path wall 8a from the ultrasonic wave generating element 9 oscillated by the control device 10. When radiated into the stock solution 2, the ultrasonic wave is reflected at the same amplitude and the same wavelength by the other channel wall 8b functioning as a reflection wall.

As a result, at the place where the stationary standing sound wave generating means 5 is installed in the flow path 4, the ultrasonic wave (incident wave) radiated from the ultrasonic wave generating element 9 and the reflected wave are combined into FIG. As shown in the outline, a stationary standing sound wave 11 in which the position of the node 12 is stationary is generated in the stock solution 2 in the flow path 4. At this time, in the stationary standing sound wave 11, the number n _{s of the} nodes 12 formed in the flow path 4 is a value obtained by dividing twice the tube diameter d by the wavelength λ _s of the ultrasonic wave ( n _s = 2d / λ _s ).

However, it is desirable that the number n _{s of} nodes 12 formed in the flow path 4 of the stationary standing sound wave 11 is set to be larger than 1 (n _s > 1). This is because, when the number of nodes 12 of the stationary standing sound wave 11 is one (n _s = 1), the particles 3 contained in the stock solution 2 flowing in the flow path 4 are separated from the stationary standing sound wave 11. If one node 12 can be supplemented, the particles 3 can be aggregated in one place. However, as described above, the movement distance for moving the particles 3 to the one node 12 in the flow path 4 is long. This is because there is a possibility that trapping of the particles 3 may occur. On the other hand, if the number n _{s of} nodes 12 formed in the flow path 4 of the stationary standing sound wave 11 is greater than 1, the plurality of nodes 12 are dispersed and arranged in the flow path 4. 3 is more easily captured, which is advantageous when a continuous solid-liquid separation process for a large amount of stock solution 2 is efficiently performed.

In FIG. 1, as an example, the setting location of the stationary standing sound wave generating means 5 in the flow path 4 is set so that the wavelength λ _{s of the} ultrasonic wave radiated from the ultrasonic wave generating element 9 matches the tube diameter d. 6 shows a state in which the stationary standing sound wave 11 having the number n _s of the nodes 12 of 2 is generated.

  Therefore, in the stationary standing sound wave generating means 5, as shown in FIG. 1, when the stock solution 2 continuously supplied from the upstream side of the flow path 4 reaches the generation point of the stationary standing sound wave 11, An acoustic radiation force is applied to the particles 3 contained in the stock solution 2 so that the particles 3 can be trapped and gathered in each node 12 of the stationary standing sound wave 11.

  Further, in the stationary standing sound wave 11, the particles 3 captured by the nodes 12 as described above are densely gathered at the positions of the nodes 12, thereby promoting aggregation of the particles 3, A particle group 3 a having an increased particle size is formed by aggregation of the particles 3.

When the particles 3 in the stock solution 2 are captured by the nodes 12 of the stationary standing sound wave 11 as described above, the length of the flow path 4 necessary for separating the particles 3 from the liquid serving as the dispersion medium. The size may be appropriately determined according to the acoustic radiation force F _ac expressed as follows and the flow velocity.

In the above description, when φ> 0, the particle 3 moves to the node 12 of the stationary standing sound wave 11, and when φ <0, the particle 3 moves to the belly. Here, if φ> 0, for example, if there is no solid-liquid density difference, γ _w > γ _c . γ is a compression rate [m ² / N] (more precisely, an elastic compliance constant (= reciprocal of elastic modulus)). Generally, the compression ratio is φ> 0 because the liquid is larger than the solid. Therefore, in the following description and drawings, the case where φ> 0 is considered.

The stationary standing sound wave 11 is set so that the wavelength λ _s is set to the long wavelength side within the range of the predetermined setting condition so that the number n _{s of} nodes 12 formed in the flow path 4 is reduced. Since more particles 3 are captured by one node 12, the aggregation rate of the particles 3 can be increased.

However, when the number n _s of nodes 12 of the stationary standing sound wave 11 is set to be small as described above, the stock solution 2 flowing through the flow channel 4 generates the stationary standing sound wave 11 in the flow channel 4. It is necessary to set a long time to pass through the region (hereinafter referred to as the sound wave region). That is, the fact that the number n _{s of the} nodes 12 is small means that the distance between the nodes 12 is increased. In addition, a long wavelength leads to a small acoustic radiation force. Therefore, in this case, since the moving speed of the particles 3 to the nodes 12 is reduced, the moving distance to the nodes 12 is increased, so that the time required for the particles 3 in the stock solution 2 to move to the nodes 12 is long. Become. Therefore, if the particle 3 in the stock solution 2 passes through the region where the acoustic radiation force by the stationary standing sound wave 11 acts (that is, the sound wave region) is short, the particle 3 is stationary before moving to the node 12. It flows out of the range where the acoustic radiation force of the standing sound wave 11 works and cannot be aggregated into the nodes 12. Therefore, when the number n _s of the nodes 12 of the stationary standing sound wave 11 is set to be small, the time for the particle 3 to pass through the sound wave region is set as compared with the case where the number n _{s of the} nodes 12 is set to be large. Need to be long. As a specific configuration in this case, the sound wave region of the stationary standing sound wave 11 is set longer in the upstream and downstream direction of the flow path 4 or the flow rate of the stock solution 2 is decreased so that the particles 3 What is necessary is just to ensure the time for moving to the node 12. Of the two configurations described above, from the viewpoint of efficiently performing continuous solid-liquid separation processing for a large amount of the stock solution 2, the sound wave region of the stationary standing sound wave 11 is defined as the flow path 4. A configuration in which the length is set longer in the upstream / downstream direction is more desirable.

On the other hand, in the stationary standing sound wave 11, when the frequency f _s of the ultrasonic wave is set on the high frequency side, the acoustic radiation force increases because the wave number k is proportional to the frequency f _s . Particles 3 can be rapidly aggregated into nodes 12. When the frequency f _{s of the} ultrasonic wave is set on the high frequency side, many nodes 12 of the stationary standing sound wave 11 are formed in the flow path 4. This also makes it possible to quickly aggregate the particles 3 in the stock solution 2 onto the nodes 12 of the stationary standing sound wave 11 with a short moving distance.

  The moving standing sound wave generating means 6A and 6B are provided in the flow path 4 at the downstream side of the installation position of the stationary standing sound wave generating means 5 in a single or a plurality in the upstream / downstream direction. FIG. 1 shows an example in which two moving standing sound wave generating means 6A and 6B are arranged in an upstream / downstream direction.

  The moving standing sound wave generating means 6A and 6B are respectively composed of ultrasonic wave generating elements 13A and 13B such as piezoelectric elements (piezo elements) and control devices 14A and 14B connected to the ultrasonic wave generating elements 13A and 13B. It is set as the structure provided with.

  Each of the ultrasonic wave generating elements 13A and 13B is attached to the outer surface of one flow path wall 8a of the flow path 4 in the same manner as the ultrasonic wave generating element 9 of the stationary standing sound wave generating means 5.

  As long as each of the ultrasonic generating elements 13A and 13B can generate an inverse piezoelectric phenomenon and oscillate an ultrasonic wave having a desired frequency to be described later in the flow path 4, a ceramic system, a crystal system, Any kind of element known as a piezoelectric element, such as a resin system or a resin-ceramic composite system, may be used.

  Each of the control devices 14A and 14B applies a voltage to the corresponding ultrasonic generating elements 13A and 13B to generate ultrasonic vibration based on the reverse piezoelectric phenomenon, and individually controls the frequency of the ultrasonic vibration. As a result, ultrasonic waves that periodically change the frequency can be emitted from the ultrasonic wave generating elements 13A and 13B into the stock solution 2 in the flow path 4 as described later. It is. As a result, the ultrasonic wave (incident wave) radiated from the ultrasonic wave generating elements 13A and 13B and the other flow path wall at the installation location of the moving standing sound wave generating means 6A and 6B in the flow path 4 By synthesizing with the reflected wave generated when 8b becomes a reflecting wall, the position of the node 16 is changed from the one channel wall 8a side to the other channel wall 8b as shown by a white arrow in FIG. The moving standing sound waves 15 that are periodically moved to the side can be individually generated (generated).

  Here, the moving standing sound wave 15 generated by each of the moving standing sound wave generating means 6A and 6B will be described in detail.

As described above, the moving standing sound wave 15 is schematically shown in FIG. 2 in order to periodically move the position of the node 16 from the one channel wall 8a side to the other channel wall 8b side. to, from an initial frequency f ₁ in the step 1, by increasing the frequency by a frequency step width Δf for each step of the time step Delta] t, the frequency change to vary to a final frequency f _iMax as the highest frequency in the last step iMax of 1 cycle The cycle is repeated.

Details will be described below.
In the moving standing sound wave 15, the distance L (m) from the origin of the m-th node 16 with the position of the other flow path wall 8 b as the origin is
L (m) = (2m−1) · (λ / 4) (where m ≧ 1) (1)
It is represented by Further, the distance l (m) from the origin to the m-th antinode (including the antinode of the other channel wall 8b) is:
l (m) = (m−1) · (λ / 2) (where m ≧ 1) (2)
It is represented by

  Here, the number of steps is indicated by i (i = 1, 2,..., IMax), and the particle group 3a captured by the node 16 of the moving standing sound wave 15 formed in a certain step is represented as follows. The condition for moving the node 16 of the moving standing sound wave 15 formed in the next step to increase the frequency with the frequency step size Δf toward the other channel wall 8b without being dispersed is as follows. These are the three conditions. In the following description, the node 16 and the antinode number m indicate the order counted from the origin. Further, the subscripts attached to the node 16 and the antinode number m, the number n of the nodes 16 and the frequency f indicate that each is related to the moving standing sound wave 15 when the number of steps is indicated by the subscript. . Furthermore, all the expressions in which (i-1) is used as a subscript are assumed to have a condition of i ≧ 2.

The _mi- th node 16 of the moving standing sound wave 15 in step i is the node 16 closest to the mi _-first node 16 of the moving standing sound wave 15 in the previous step (i-1).

The first condition in the moving standing wave 15, the distance from the origin of the m _i th section 16 when step i after the frequency change, m _i when the frequency change before step (i-1) The distance from the origin of the _-1st node 16 is smaller (where i ≧ 2). This first condition is expressed by the following equation.
L (m _i ) <L (m _i-1 ) (3)

The second condition is that in the moving standing sound wave 15, the distance from the origin of the (m _i +1) -th antinode in the step i is the m _i-1 th _- th in the step (i-1). This is to be larger than the distance from the origin of node 16 (where i ≧ 2). This second condition is expressed by the following equation.
l ((m _i +1))> L (m _i-1 ) (4)

The third condition is that the number n _i−1 (where i ≧ 2) of the nodes 16 of the moving standing sound wave 15 is set to 2 or more. This is because, as will be described later, in the moving standing sound wave 15, the particle group 3a captured by a plurality of nodes 16 is moved to a smaller number of nodes 16 to concentrate (aggregate) the particle group 3a. This is because the moving standing sound wave 15 needs to have a plurality of nodes 16 for the purpose of illustration. Since the number m _{i given} to the node 16 of the moving standing sound wave 15 is within the number n _i of the node 16 at that time, the third condition is as follows.
2 ≦ m _i-1 ≦ n _i-1 (5)

となり、ステップｉでの周波数ｆ_iは、ｆ_i＝ｆ_i-1＋Δｆ_iで示されるため、

となる。 From the above formula (3) and formula (4),

Next, the frequency f _i at step i, because represented by f _i = f _i-1 + Delta] f _i,

It becomes.

Therefore, the Δf _i may be set so that m _i satisfying the above equation (7) exists under the condition of the above equation (5).

  Here, in order to simplify the control of the frequency change of the moving standing sound wave 15 in each of the moving standing sound wave generating means 6A and 6B, consider a case where control for gradually increasing the frequency f is performed.

In this case, since m _i-1 ≦ m _i ,
m _i −m _i−1 = N = 0, 1, 2,...
Then, the above formula (7) becomes as follows.

By the way, it is preferable that the frequency step width Δf _i is as small as possible because the frequency f _i at step i after the frequency change is difficult to increase. This is because, as the frequency f of the moving standing sound wave 15 increases, the energy required to generate the moving standing sound wave 15 increases, so it is effective to keep the frequency f small in order to reduce energy consumption. It depends. Therefore, it is optimal to set N to N = 0.

となる。 Therefore, when N = 0 is substituted into the above equation (8),

It becomes.

となる。 As shown in the above formula (5), since m _i-1 ≦ n _i-1 ,

It becomes.

となる。よって、上記式（９）より、以下のΔｆ_iの条件式が導かれる。

Further, as described above, since the moving standing sound wave 15 increases the frequency f at each step from step 1 to step iMax as described above, the frequency f i of the moving standing sound wave 15 at the time of step _i. Is greater than or equal to the initial frequency f ₁ . Further, the number n _i of the nodes 16 of the moving standing sound wave 15 is the maximum value of the number n _iMax of the nodes 16 at the step iMax. This
f ₁ ≦ f _i-1
n _iMax ≧ n _i-1 (∵ (1 / n _iMax ) ≦ (1 / n _i-1 ))
Because

It becomes. Therefore, the following conditional expression of Δf _i is derived from the above equation (9).

From the above equation (12), Δf _i can be determined by the frequency f ₁ in step ₁ and the number n _iMax of nodes 16 at step iMax.

  The conditions for step iMax may be set as follows, for example.

That is, the number of nodes 16 at the position farthest from the other flow path wall 8b in the moving standing sound wave 15 in step 1 (initial frequency f ₁ ), that is, the number of nodes 16 in the moving standing sound wave 15 in step 1. The number of the node 16 to which the particle group 3a captured in the node 16 of the order m ₁ (= n ₁ ) equal to n ₁ moves at the step _iMax is set to _{mi max} .

In the step iMax, the frequency is set such that the distance from the origin of the m _imax th node 16 is smaller than the distance from the origin in the step 1 to the n _1st (m ₁ = n ₁ ) antinode. f Set _iMax . This condition is as follows according to the above equations (1) and (2).
L (m _iMax ) <l (m ₁ = n ₁ ) (13)

となる。 When the above equation (13) is transformed using the relationship of sound velocity c = wavelength λ × frequency f,

It becomes.

となる。よって、この場合は、ｆ_iMaxを、ステップ１のときの移動定在音波１５の初期周波数ｆ₁、及び、節１６の数ｎ₁を基にして決定することができる。 Further, the above equation (14) is obtained when m _iMax = n ₁ , that is, when N = 0,

It becomes. Therefore, in this case, f _iMax can be determined based on the initial frequency f ₁ of the moving standing sound wave 15 in step 1 and the number n _{1 of} nodes 16.

As a result, the moving standing acoustic wave 15 changes (increases) the frequency from the initial frequency f ₁ as described above by the predetermined frequency increment Δf _i set as described above, and thereby the predetermined final frequency f. After changing until reaching _iMax , an operation of returning from the final frequency f _iMax to the initial frequency f ₁ to complete one frequency change cycle, during the one frequency change cycle, The particle group 3a captured by the m-th (m ≧ 2) node 16 from the other channel wall 8b of the moving standing sound wave 15 is moved to the m-th in the moving standing sound wave 15 returned to the initial frequency f _1. It can be made to be captured by another numbered node 16 located closer to the other flow path wall 8b.

  Therefore, in the moving standing sound wave 15, by repeating the frequency change cycle, the particle group 3 a captured by each node 16 of the moving standing sound wave 15 is gradually moved closer to the other channel wall 8 b. 16 can be concentrated.

  FIGS. 3A, 3B, 3C, 3D, and 3E show an outline of the frequency change cycle of the moving standing sound wave 15. FIG.

FIG. 3A shows a step in which the initial frequency f ₁ of the moving standing sound wave 15 is set to the same frequency as the frequency f _s of the stationary standing sound wave 11 shown in FIG. 1 at the time t = 0 in FIG. The state of 1 is shown. Therefore, in the moving standing sound wave 15, two nodes (n ₁ = 2) nodes 16 similar to the number n _s of the nodes 12 of the stationary standing sound wave 11 shown in FIG. It becomes a state.

It is assumed that the frequency step Δf _i of the frequency change cycle of the moving standing sound wave 15 is set based on the setting condition equation (10) described above.

FIG. 3B shows a step 2 in which the frequency f ₂ of the moving standing sound wave 15 is changed to f ₁ + Δf ₂ when the time step Δt has elapsed from the start of step 1 as shown in FIG. This shows the state. At this time, as shown in FIG. 3 (b), in the moving standing sound wave 15 of step 2, a third node 16 is newly added at a position corresponding to one flow path wall 8a as the frequency changes. From the position of the node 16 that has been formed second from the other channel wall 8b at the time of Step 1, the second node from the other channel wall 8b at Step 2 is formed. 16 is closer. For this reason, in the moving standing sound wave 15, when the frequency is changed as in Step 2, the particle group 3a captured by the node 16 in Step 1 is positioned closer to the other channel wall 8b. You can move up to 16.

FIG. 3 (c) shows a step 3 in which the frequency f ₃ of the moving standing sound wave 15 is changed to f ₂ + Δf ₃ when the time step Δt has elapsed from the start of step 2 as shown in FIG. This shows the state. Also in this step 3, in the moving standing acoustic wave 15, as in the case of the frequency change from step 1 to step 2, the particle group 3a captured by the node 16 in step 2 is more separated from the other flow. It can be moved to the node 16 located near the road wall 8b.

In the moving standing sound wave 15 of step 3 in the state shown in FIG. 3C, f ₃ = (3/2) f ₁ , so that it _satisfies the above-mentioned setting condition formula of the final frequency f _iMax. do not do.

Therefore, as shown in FIG. 3D, the moving stationary sound wave 15 is further moved as step 4 when the time step Δt has elapsed from the start of step 3 as shown in FIG. The frequency f _{4 of the} sound wave 15 is changed to f ₃ + Δf ₄ .

  Also in this step 4, in the moving standing sound wave 15, as in the case of the frequency change from step 2 to step 3, the particle group 3 a captured by the node 16 in step 3 is more separated from the other flow. It becomes possible to move to the node 16 located closer to the road wall 8b.

Since the frequency f 4 of the moving standing sound wave 15 in step 4 is larger than the frequency f ₃ , the frequency f _{4 satisfies} the above-described setting condition expression of the final frequency _{fi max} .

Therefore, the moving standing sound wave 15 has the frequency f ₄ in step 4 as the final frequency _fimax , and when the time step Δt has elapsed from the start of step 4 as shown in FIG. ), The frequency of the moving standing sound wave 15 is returned to the initial frequency f ₁ . At this time, in the moving standing sound wave 15, two nodes 16 are formed again at the same position as in Step 1 shown in FIG. 3A with the return to the initial frequency f ₁ . The position of the second node 16 from the other channel wall 8b formed in the above step 4 is the same as that of the first node 16 from the other channel wall 8b in the step 1. It is closer to the second node 16 than the wall 8b. Therefore, in the moving standing sound wave 15, if the frequency is suddenly changed to the initial frequency f _{1 of} Step 1 after the frequency change of Step 1 to Step 4 is performed, from Step 1 to Step 4 described above. During this period, the particle group 3a captured by the second node 16 from the other channel wall 8b can be moved to the first node 16 positioned closer to the other channel wall 8b.

  Therefore, in the moving standing sound wave 15, the frequency change cycle from step 1 to step 4 shown in FIGS. 3A, 3B, 3C, and 3D is repeated as shown in FIG. By carrying out, when the aggregated particle group 3a of the particles 3 captured by the stationary standing sound wave 11 is captured by the node 16 of the moving standing sound wave 15, the captured particle group 3a is It can be gradually concentrated to the first node 16 from the flow path wall 8b.

  In the frequency change cycle of the moving standing sound wave 15, the time step Δt for changing the frequency by the frequency step width Δf is such that the larger the time step Δt is, the closer the particle group 3a is to the other channel wall 8b. The time required for moving and concentrating becomes longer, and the processing speed of the solid-liquid separation process decreases. Therefore, the time increment Δt may be appropriately set according to the processing speed required for the solid-liquid separation of the particles 3 (particle group 3a) of the stock solution 2.

  By the way, the time step Δt is set according to the processing speed required for the solid-liquid separation as described above. At this time, the moving speed of the particle group 3a (particle 3) is low, and If the position of the node 16 changes before the particle 3 (particle group 3a) aggregates to the position of the node 16 that is displaced with the frequency change of the moving standing sound wave 15 every time step Δt, the particle 3 Aggregation of (particle group 3a) becomes difficult.

  As one method for avoiding the possibility of such a problem, for example, the frequency of the moving standing sound wave 15 is increased. In this case, since the acoustic radiation force increases as the frequency of the moving standing sound wave 15 increases, the particles 3 (particle group 3a) can easily move to the node 16.

  As another method for avoiding the possibility of the above problem, the frequency step width Δf when changing the frequency of the moving standing sound wave 15 may be set small within the above-described setting conditions. Good. In this case, since the displacement amount of the node 16 accompanying the frequency change for each step of the moving standing sound wave 15 is reduced, the moving time for the particle 3 (particle group 3a) to move to the node 16 is shortened for each step. be able to.

  Further, the concentrated particle outlet 7 is located at a position downstream of the moving standing sound wave generating means 6B in the flow path 4 and corresponding to the first node 16 from the other flow path wall 8b of the moving standing sound wave 15. It is provided so that the liquid flowing through can be separated. As a result, the concentrated particle outlet 7 is concentrated at the position of the node 16 near the other channel wall 8b as described above by the moving standing sound wave 15 generated by the moving standing sound wave generating means 6A and 6B. The particles 3 (particle group 3a) can be taken out together with a part of the liquid.

  On the other hand, the remaining liquid that is not collected through the concentrated particle outlet 7 is guided to the downstream portion of the flow path 4 as a clarified liquid 17 in which the particles 3 are relatively clarified, and can be collected. .

  In the above, the moving standing sound wave 15 generated by the moving standing sound wave generating means 6A and 6B is used to move the particle group 3a in which the particles 3 captured by the node 12 of the upstream stationary standing sound wave 11 are aggregated. From the viewpoint of enabling the single sound wave 16 to be captured without being dispersed in the multiple sound waves 16 of the standing sound wave 15, the moving sound wave 15 generated at every step is the same. It is desirable that the distance from the other flow path wall 8b of each antinode does not coincide with the distance from the other flow path wall 8b of each node 12 of the stationary standing sound wave 11.

となる。 When this condition is expressed by an expression,

It becomes.

  When the solid-liquid separation process of the particles 3 from the stock solution 2 is performed using the solid-liquid separation device 1 of the present invention having the above-described configuration, a liquid such as the stock solution 2 or the The stock solution 2 is filled with a liquid serving as a dispersion medium for the particles 3. Next, the stationary standing sound wave generating means 5 and the moving standing sound wave generating means 6A, 6B are respectively operated, and in the flow path 4, the respective standing sound wave generating means 5, 6A, 6B are placed at the installation locations. Thus, the stationary standing sound wave 11 and the two moving standing sound waves 15 are generated in a state of being arranged in order from the upstream side.

  Thereafter, the stock solution 2 to be subjected to the solid-liquid separation process is continuously supplied from the upstream side.

  When the stock solution 2 reaches the location where the stationary standing sound wave 11 is generated, the particles 3 contained in the stock solution are affected by the acoustic radiation force of the stationary standing sound wave 11 and the stationary standing sound wave 11 is affected. The sound wave 11 is moved to the position of each node 12 and is captured by each node 12. Further, at the positions of the nodes 12, the trapped particles 3 are concentrated to promote aggregation of the particles 3 to form a particle group 3a having an increased particle size.

  Thereafter, the particle group 3 a is moved downstream by the flow of the stock solution 2 in the flow path 4. The particle group 3 a moving in this way is captured by the node 16 of the moving standing sound wave 15 when reaching the location where the moving standing sound wave 15 is generated. The particle group 3a captured by the node 16 of the moving standing sound wave 15 is gradually concentrated in the node 16 near the other channel wall 8b as the frequency change cycle of the moving standing sound wave 15 is repeated. And become concentrated.

  At this time, the particle group 3a is formed by aggregation of the particles 3, and the particle diameter is increased as compared with the single particle 3. Therefore, in the moving standing acoustic wave 15, the particle group 3a On the other hand, the influence of the acoustic radiation force can be given more strongly than that for the single particle 3. Therefore, the particle group 3 a can be efficiently concentrated by the moving standing sound wave 15.

  Furthermore, since the moving standing sound wave generating means 6A and 6B are provided in two stages in the upstream and downstream direction of the flow path 4, the particle group 3a is more reliably concentrated on the other flow path wall 8b side. Will be able to.

  After that, when the particle group 3a concentrated as described above is moved downstream by the liquid flow in the flow path 4, the particle group 3a reaches the concentrated particle outlet 7, so the concentrated particle outlet 7 Further, the concentrated particle group 3 a is separated and collected together with a part of the liquid, and separated from the clarified liquid 17 guided to the downstream portion of the flow path 4.

  Thus, according to the solid-liquid separation method and apparatus of the present invention, the acoustic radiation force of the stationary standing sound wave 11 and each moving standing sound wave 15 is applied to the particles 3 (particle group 3a) in the stock solution 2 flowing through the flow path. The continuous solid-liquid separation process in which the particles 3 (particle group 3a) are concentrated and separated from the clarified liquid 17 can be efficiently performed.

  Further, since the solid-liquid density difference is not required in the solid-liquid separation process, the solid-liquid separation is also performed for the particles 3 that have no density difference with the liquid serving as the dispersion medium of the particles 3 or have a very small density difference. Can be implemented efficiently.

  In addition, the particles 3 are aggregated by using the stationary standing sound wave 11 to form a particle group 3a having an increased particle diameter, and then the moving standing sound wave 15 is concentrated near the other channel wall 8b. Therefore, the concentration of the particle group 3a can be efficiently carried out, and the efficiency of solid-liquid separation can be further enhanced.

  Therefore, the solid-liquid separation method and apparatus according to the present invention include sand, clay, colloid, etc. contained in water as a pretreatment for desalination of seawater or shale gas-associated water by a reverse osmosis membrane method or a forward osmosis membrane method. Suitable for processing to separate and remove solid particles such as algae and other microorganisms, dead bodies and metabolites thereof, or to separate algae, cells and microorganisms from water (in the culture medium) Solid-liquid separation treatment can be performed.

  Furthermore, in the solid-liquid separation method and apparatus of the present invention, the flow path 4 is provided with the generation location of the stationary standing sound wave 11 and the generation location of the moving standing sound wave 15 in multiple stages. Even if there is a particle 3 that cannot be completely captured by the node 12 of the standing sound wave 11, the particle 3 can be captured by the node 16 of the moving standing sound wave 15 for separation, and the efficiency of solid-liquid separation can be achieved. Can be increased. Therefore, the solid-liquid separation method and apparatus of the present invention can increase the flow rate of the stock solution 2 in the flow path 4 and can be advantageous for expansion of the solid-liquid separation processing amount per unit time. Therefore, the solid-liquid separation method and apparatus of the present invention can be effective for continuous processing of solid-liquid separation of the stock solution 2.

  Next, FIG. 4 thru | or FIG. 6 (a) (b) (c) (d) (e) shows another example of a solid-liquid separator as another form of implementation of this invention.

  That is, the solid-liquid separation device of the present embodiment is indicated by reference numeral 1A in FIG. 4. In brief, in the same configuration as the solid-liquid separation device 1 shown in FIG. 6B is replaced with a configuration in which a moving standing sound wave 15 of a type in which the position of the node 16 is periodically moved from one channel wall 8a side to the other channel wall 8b side is generated in FIG. As indicated by the white arrow, it is possible to individually generate (generate) moving standing sound waves of a type in which the position of the node 16 is periodically moved from the other channel wall 8b side to the one channel wall 8a side. The mobile standing sound wave generating means 6C and 6D are configured to be configured.

  Further, at the downstream side position of the moving standing sound wave generating means 6D closest to the downstream side in the flow path 4, the concentrated particle take-out port 7a has a node 16 (near the flow path wall 8a of the moving standing sound wave 15). It is provided so that the liquid flowing through the position corresponding to the first node 16) from one flow path wall 8a can be separated. As a result, at the concentrated particle outlet 7a, as the node 16 of the moving standing sound wave 15 generated by the moving standing sound wave generating means 6C, 6D moves periodically as described above, The particles 3 (particle group 3a) concentrated at the position of the node 16 can be taken out together with a part of the liquid.

  On the other hand, the remaining liquid that is not collected through the concentrated particle outlet 7a is guided to the downstream portion of the flow path 4 as a clarified liquid 17 in which the particles 3 are relatively clarified, and can be collected. It is as.

  Here, the moving standing sound wave 15 generated by each of the moving standing sound wave generating means 6C and 6D will be specifically described.

In the present embodiment, as described above, the moving standing sound wave 15 is used to periodically move the position of the node 16 from the other channel wall 8b side to the one channel wall 8a side. 5 as outlined, from the initial frequency f ₁ in the step 1, by decreasing the frequency by the frequency step width Δf for each step of the time step Delta] t, the lowest frequency in the last step iMax one cycle final frequency f _The frequency change cycle for changing to _iMax is repeated.

Here, the number of steps is indicated by i (i = 1, 2,..., IMax), and the particle group 3a captured by the node 16 of the moving standing sound wave 15 formed in a certain step is represented as follows. The condition for moving the node 16 of the moving standing sound wave 15 formed in the next step of decreasing the frequency with the frequency step size Δf toward the one channel wall 8a without being dispersed is as follows. These are the three conditions. Note that the _mi- th node 16 of the moving standing sound wave 15 in step i is the node 16 closest to the mi _-first node 16 of the moving standing sound wave 15 in the previous step (i-1). To do.

The first condition in the moving standing wave 15, the distance from the origin of the m _i th section 16 when step i after the frequency change, when the previous frequency change step (i-1) m The distance is greater than the distance from the origin of the ( _i-1) th node 16 (where i ≧ 2). This first condition is expressed by the following equation.
L (m _i )> L (m _i-1 ) (16)

The second condition, in the above mobile standing wave 15, the distance from the origin of the m _i th belly in step i is a m _i-1 th node 16 when in step (i-1) The distance is smaller than the distance from the origin (where i ≧ 2). This second condition is expressed by the following equation.
l (m _i ) <L (m _i-1 ) (17)

The third condition is that the number n _i−1 (where i ≧ 2) of the nodes 16 of the moving standing sound wave 15 is set to 2 or more. This is because, as will be described later, in the moving standing sound wave 15, the particle group 3a captured by a plurality of nodes 16 is moved to a smaller number of nodes 16 to concentrate (aggregate) the particle group 3a. This is because the moving standing sound wave 15 needs to have a plurality of nodes 16 for the purpose of illustration. Since the number m _{i given} to the node 16 of the moving standing sound wave 15 is within the number n _i of the node 16 at that time, the third condition is as follows.
2 ≦ m _i-1 ≦ n _i-1 (18)

となり、ステップｉでの周波数ｆ_iは、ｆ_i＝ｆ_i-1−Δｆ_iで示されるため、

となる。 The above equations (16) and (17) are obtained from the above equations (1) and (2).

Next, the frequency f _i at step i, because represented by f _i = f _i-1 -.DELTA.f _i,

It becomes.

Therefore, the Δf _i may be set so that m _i satisfying the above equation (20) exists under the condition of the above equation (18).

  Here, in order to simplify the control of the frequency change of the moving standing sound wave 15 in each of the moving standing sound wave generating means 6C and 6D, consider the case where the control for gradually decreasing the frequency f is performed.

In this case, since m _i-1 ≧ m _i ,
m _i−1 −m _i = N = 0, 1, 2,...
Then, the above equation (20) becomes as follows.

となる。 Substituting N = 0 into the above equation (21),

It becomes.

となる。 As shown in the above equation (18), m _i-1 ≦ n _i-1 .

It becomes.

となる。よって、上記式（２３）より、以下のΔｆ_iの条件式が導かれる。

Further, as described above, since the moving standing sound wave 15 decreases the frequency f for each step from step 1 to step iMax, the frequency f iMax of the moving standing sound wave 15 at the time of step _iMax. Is less than or equal to the initial frequency f _i-1 (where i ≧ 2). In the moving standing sound wave 15, the number n _{i of the} nodes 16 tends to decrease as the number of steps i increases. This
f _iMax ≦ f _i-1
n _i-1 ≧ n _i
Because

It becomes. Therefore, the following conditional expression of Δf _i is derived from the above equation (23).

From the above equation (25), Δf _i can be determined by the number n ₁ of nodes in step ₁ and the frequency f _{iMax at} step iMax.

  The conditions for step iMax may be set as follows, for example.

That is, among the nodes 16 of the moving standing sound wave 15 in step 1 (initial frequency f ₁ ) at the position closest to the other flow path wall 8b in the moving standing sound wave 15, that is, the node 16 of the moving standing sound wave 15 in step 1 The number of the node 16 to which the particle group 3a captured in the node 16 of the order m ₁ (= 1) moves at the step iMax is m _iMax .

In the step iMax, the frequency f _{iMax is set} so that the distance from the origin of the m _iMax th node 16 is larger than the distance from the origin in the step 1 to the second (m ₁ = 2) _antinode. Set. This condition is as follows according to the above equations (1) and (2).
L (m _iMax )> l (m ₁ = 2) (26)

となる。 When the above equation (26) is transformed using the relationship of sound velocity c = wavelength λ × frequency f,

It becomes.

Therefore, in this case, f _iMax can be determined based on the initial frequency f ₁ of the moving standing sound wave 15 at step 1.

As a result, the moving standing acoustic wave 15 changes (decreases) the frequency from the initial frequency f ₁ as described above by the predetermined frequency increment Δf _i set as described above, and thereby the predetermined final frequency f. After changing until reaching _iMax , an operation of returning from the final frequency f _iMax to the initial frequency f ₁ to complete one frequency change cycle, during the one frequency change cycle, The particle number 3a captured by the m-th (m ≧ 1) node 16 from the other channel wall 8b of the moving standing sound wave 15 is the original number in the moving standing sound wave 15 returned to the initial frequency f ₁ . It can be made to be captured by another numbered node 16 located closer to one flow path wall 8a than the other node 16.

  Therefore, in the moving standing sound wave 15, by repeating the frequency change cycle, the particle group 3 a captured by each node 16 of the moving standing sound wave 15 gradually becomes a node near the one channel wall 8 a. 16 can be concentrated.

  6A, 6 </ b> B, 6 </ b> C, 6 </ b> D, and 6 </ b> E show an outline of a frequency change cycle of the moving standing sound wave 15.

FIG. 6A shows a step in which the initial frequency f ₁ of the moving standing sound wave 15 is set to the same frequency as the frequency f _s of the stationary standing sound wave 11 shown in FIG. 1 at the time t = 0 in FIG. The state of 1 is shown. Therefore, the moving standing sound wave 15 is in a state where four (n ₁ = 4) nodes 16 are formed in the flow path 4.

It is assumed that the frequency increment Δf _i of the frequency change cycle of the moving standing sound wave 15 is set based on the setting condition equation (25) described above.

Thereafter, as shown in FIG. 5, every time the time step Δt elapses from the start of step 1, the frequency of the moving standing sound wave 15 is changed to f ₂ (= f ₁ −Δf ₂ ) in steps 2, 3, and 4. , F ₃ (= f ₂ −Δf ₃ ), and f ₄ (= f ₃ −Δf ₄ ) are sequentially changed (decreased), as shown in FIGS. 6 (b), 6 (c), and 6 (d). The position of the node of the sound wave 15 is changed. As a result, in the moving standing sound wave 15, the particle group 3 a captured by the node 16 in step 1 is moved to the node 16 positioned closer to the one channel wall 8 a by steps 2, 3, and 4. Can be made.

Frequency f ₄ of the moving standing wave 15 in step 4, if it conforms to the set condition of the final frequency f _iMax described above, as shown in FIG. 5, the time increment Δt from the start of step 4 has elapsed At the time, as shown in FIG. 6E, the frequency of the moving standing sound wave 15 is returned to the initial frequency f ₁ . At this time, in the moving standing acoustic wave 15, four nodes 16 are formed again at the same position as in Step 1 shown in FIG. 6A with the return to the initial frequency f ₁ . The position of the first node 16 from the other channel wall 8b formed in step 4 is the same as that of the second node 16 in step 1 than the other channel wall 8b. It is closer to the first node 16 than the wall 8b. Therefore, in the moving standing sound wave 15, if the frequency is suddenly changed to the initial frequency f _{1 of} Step 1 after the frequency change of Step 1 to Step 4 is performed, from Step 1 to Step 4 described above. During this period, the particle group 3a captured by the first node 16 from the other channel wall 8b can be moved to the second node 16 from the other channel wall 8b. In the moving standing sound wave 15, when the frequency is suddenly changed to the initial frequency f _{1 of} Step 1 after the frequency change of Step 1 to Step 4 is performed, FIGS. 6A and 6B. (C) As shown in (d) and (e), the particle group 3a captured by the node 16 having the order larger than the second channel wall 8b from the other flow path wall 8b is made to flow in the most It can be moved to the node 16 formed at a position close to the road wall 8a.

Therefore, in the moving standing wave 15, then, as shown in FIG. 5, by repeating the frequency change cycle from step 1 shown in FIG. 6 (a) (b) ( c) (d) to step 4 By carrying out, when the aggregated particle group 3a of the particles 3 captured by the stationary standing sound wave 11 is captured by the node 16 of the moving standing sound wave 15, the captured particle group 3a is The node 16 near the flow path wall 8a can be gradually concentrated.
Other configurations are the same as those shown in FIGS. 1 to 3A, 3B, 3C, 3D, and 3E, and the same components are denoted by the same reference numerals.

  The solid-liquid separation device 1A of the present embodiment having the above-described configuration is similar to the solid-liquid separation device 1 of the embodiments of FIGS. 1 to 3 (a), (b), (c), (d), and (e). When used, the particles are captured at each node 12 of the stationary standing sound wave 11 by the acoustic radiation force of the stationary standing sound wave 11, and the captured particles 3 are densely packed. Aggregation between the particles can be promoted to form a particle group 3a having an increased particle size.

  After that, when the particle group 3a reaches the location where the moving standing sound wave 15 is generated by the flow of the stock solution 2 in the flow path 4, the particle group 3a captured by the node 16 of the moving standing sound wave 15 is captured. As the frequency change cycle of the moving standing sound wave 15 is repeated, the node 16 near the one channel wall 8a can be gradually concentrated and concentrated. Therefore, the concentrated particle group 3a can be separated and collected together with a part of the liquid from the concentrated particle outlet 7a and separated from the clarified liquid 17 guided to the downstream portion of the flow path 4. Can do.

  As described above, the present embodiment can provide the same effects as those of the embodiments of FIGS. 1 to 3A, 3B, 3C, 3D, and 3E.

  The present invention is not limited only to the above-described embodiment, and the flow path 4 includes the ultrasonic wave generation of the stationary standing sound wave generating means 5 and the moving standing sound wave generating means 6A, 6B, or 6C, 6D. If the one flow path wall 8a for installing the elements 9, 13A, 13B for use and the other flow path wall 8b to be the ultrasonic reflection wall are arranged so as to face each other, the cross-sectional shape is appropriately changed. May be.

The frequency f _s of the stationary standing sound wave 11 generated in the flow path 4 depends on the cross-sectional area and cross-sectional shape of the flow path 4, the flow rate of the stock solution 2 supplied to the flow path 4, and the like. You may change suitably so that the number of the nodes 12 formed inside may be 1 or 3 or more.

The initial frequency f ₁ of the moving standing sound wave 15 generated in the flow path 4 depends on the cross-sectional area and cross-sectional shape of the flow path 4, the flow rate of the stock solution 2 supplied to the flow path 4, and the like. 4 may be appropriately changed so that the number of nodes 16 formed in 4 is a plurality other than that illustrated.

  The distance between the stationary standing sound wave generating means 5 and the moving standing sound wave generating means 6A and 6B or 6C and 6D installed in the flow path 4 in the upstream and downstream direction of the flow path 4 is a stock solution supplied to the flow path 4. 2 may be set as appropriate according to the flow rate of 2, the solid-liquid separation efficiency of the required particle group 3a (particles 3), the concentration rate, and the like.

  The moving standing sound wave generating means 6A and 6B, or 6C and 6D are configured so that the cross-sectional area and the cross-sectional shape of the flow path 4 and the particle group 3a (particle 3) included in one moving standing sound wave generating means are the other flow. Depending on the ability to move closer to the road wall 8b and the required separation efficiency and concentration rate of the particle group 3a (particles 3), the downstream side of the stationary standing sound wave generating means 5 in the flow path 4 is located upstream and downstream. It is good also considering the number arrange | positioned and installed in 1 or 3 or more.

In the moving standing sound wave generating means 6A and 6B or 6C and 6D, the moving standing sound wave 15 is generated in a frequency change cycle in which the frequency is changed by a frequency step width Δf _{i for} each step of a certain time step Δt. 2 and 5, the moving standing sound wave 15 is generated in a frequency change cycle in which the frequency is continuously changed from the initial frequency f ₁ to the final frequency f _iMax , as indicated by a two-dot chain line in FIGS. It may be.

The moving standing sound wave 15 generated by the moving standing sound wave generating means 6A and 6B or 6C and 6D is a particle group 3a in which the particles 3 captured by the node 12 of the stationary stationary sound wave 11 on the upstream side are aggregated. From the viewpoint of being able to be captured by the node 16 of the moving standing sound wave 15 without being dispersed, the antinode of the moving standing sound wave 15 is not formed at a position aligned with the node 12 of the stationary standing sound wave 11. As described above, it is desirable to set the frequencies f _{1 to} f ₄ (f _iMax ) at each step. However, the position of the antinode of the moving standing sound wave 15 is formed at a position aligned with the node 12 of the stationary standing sound wave 11. May be. Even in this case, in the moving standing sound wave 15, the acoustic radiation force is applied to the particle group 3a in which the particle 3 is agglomerated by the stationary standing sound wave 11 to increase the particle size, and the node 16 is efficiently processed. The particle group 3a (particle 3) captured by the node 16 can be captured well by repeating the predetermined frequency change cycle described above, and the node 16 near the other channel wall 8b or It can be concentrated to the node 16 near the channel wall 8a.

  Each of the ultrasonic wave generating elements 9, 13A, 13B may use a magnetostrictive element instead of the piezoelectric element. When the ultrasonic generation elements 9, 13A and 13B using magnetostrictive elements are employed in this way, the corresponding control devices 10 and 14A and 14B respectively apply magnetic fields (magnetism) to the corresponding ultrasonic generation elements 9, 13A and 13B. ) To generate ultrasonic vibrations and have a function of individually controlling the frequency of the ultrasonic vibrations.

  The flow path 4 may be in a form in which the stock solution 2 is circulated by either a natural flow method or a pressure feed method. Further, when the stock solution 2 is circulated by the pressure feeding method, the flow path 4 may be freely set in the direction and inclination of the flow path 4.

  The opening shape and the flow path area of the concentrated particle outlets 7 and 7a provided in the flow path 4 are not shown depending on the desired throughput of the stock solution 2 and the separation efficiency desired for solid-liquid separation of the particles 3. Or the flow channel area may be changed as appropriate.

  The stock solution 2 may add a flocculant to promote aggregation of the particles 3 at the nodes 12 of the stationary standing sound wave 11.

  In the solid-liquid separation method and apparatus of the present invention, as long as the liquid contains particles 3 that require solid-liquid separation processing, the particles 3 are contained in a stock solution 2 containing arbitrary particles 3 or a dispersion medium other than water. You may apply to the solid-liquid separation process of the disperse | distributed stock solution 2. FIG.

  The solid-liquid separators 1 and 1A of the present invention shown in FIG. 1 and FIG. 4 have concentrated particle outlets 7 and 7a or a clarified liquid 17 from which concentrated particles 3 (particle group 3a) are recovered together with a liquid. Another solid-liquid separation device 1, 1 </ b> A of the present invention may be cascade-connected to the downstream portion of the flow path 4 to be recovered, so that the solid-liquid separation efficiency and recovery rate of the particles 3 may be further increased.

  Of course, various modifications can be made without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 1,1A Solid-liquid separation apparatus 2 Stock solution 3 Particles 3a Particle group 4 Flow path 5 Stationary standing sound wave generation means 6A, 6B, 6C, 6D Moving standing sound wave generation means 7, 7a Concentrated particle outlet 8a Flow path wall 8b Flow Road wall 11 Stationary standing sound wave 12 nodes 15 Moving standing sound wave 16 nodes

Claims (3)

A flow path for circulating a stock solution in which particles are dispersed is provided.
Particles are generated by generating stationary standing sound waves in which the position of nodes in the flow path is stationary in the flow path from the ultrasonic wave generating element and capturing and aggregating the particles in the stationary standing sound wave nodes. still standing acoustic wave generating means for forming a group is provided,
At the downstream side of the installation location of the stationary standing sound wave generating means in the flow channel, the flow channel wall side from one flow channel wall side facing the inside of the flow channel from another ultrasonic wave generating element to the other flow channel wall side A moving standing sound wave that periodically displaces the position of the knot is generated, and the aggregated particles captured by the stationary standing sound wave node are moved to the other side by the displacement of the moving standing sound wave node. setting a moving standing wave generating means for concentrating the flow channel wall,
Furthermore, a concentrated particle outlet is provided at a position downstream of the moving standing sound wave generating means in the flow channel to take out a particle group concentrated on the other channel wall side by the moving standing sound wave. A solid-liquid separation device characterized by comprising: The moving standing sound wave generating means is configured such that the position of the antinode of the moving standing sound wave generated by the moving standing sound wave generating means is generated by the stationary standing sound wave generating means with reference to the flow path wall on the other side. The solid-liquid separation device according to claim 1, wherein the frequency of the moving standing sound wave is set so as not to coincide with a node of the stationary standing sound wave to be generated. When the stock solution in which the particles are dispersed is circulated through the flow path, a stationary standing sound wave with a node position stationary is applied to the stock solution in the flow path to cause the particles in the stock solution to remain stationary. Capture and agglomerate in the sonic nodes,
Next, a moving constant is obtained by periodically displacing the position of the nodes from the flow path wall side on one side facing each other to the flow path wall side on the other side in the particle group captured and aggregated by the nodes of the stationary standing sound wave. By acting a standing sound wave, the particle group is concentrated on the channel wall side on the other side of the channel with the displacement of the node of the moving standing sound wave,
Next, the solid-liquid separation method is characterized in that the particle group concentrated by the moving standing sound wave is taken out.

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