Apparatus for separating solid in liquid

Abstract

To improve classification or separation accuracy more than before in an apparatus for separating a solid content in a liquid.SOLUTION: The apparatus for separating a solid content in a liquid includes a main body 2 having a columnar internal space 21, an inner cylinder 3 provided at the center of the internal space 21, and a treatment object supply part 1 for supplying a liquid containing the solid content to swirl along a sidewall of the internal space 21. The inner cylinder 3 is provided such that the liquid in the internal space 21 falls into the inner cylinder 3 over an overflow weir 31 at an upper end of the inner cylinder 3 and is discharged to the outside of the main body 2 through an overflow discharge path 7 connected to the lower end of the inner cylinder 3. On the side wall of the internal space 21, an adjustment liquid supply port 28 for supplying a liquid for adjusting the sedimentation state of the solid content is provided at a position lower than the height at which the liquid containing the solid content is supplied. A sediment discharge port 29 for discharging a settled solid content together with a part of the liquid in the internal space 21 is provided at the lower end of the internal space 21.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an apparatus for separating solids from a liquid. [Background technology]

[0002] For example, in gravel pits and quarries, raw water contains particles of various sizes (such as sand), as well as mud (fine particles smaller than sand) and substances with low specific gravity. In order to separate particles of the desired size from such raw water and use them as aggregate, devices such as classifiers and foreign matter removers are used. For example, when recycling rare metals, the metals contained in crushed materials such as electronic circuit boards are dissolved in an acid or alkaline solution, and then equipment is used to remove the dissolved residue from the mixture of the metal eluate and the dissolved residue, and to remove the precipitate from the metal eluate.

[0003] At the former aggregate production site, the raw water has different characteristics depending on the location where the raw materials are collected. 1. The amount of river gravel and sand used as high-quality aggregates has decreased dramatically in recent years due to regulations on their collection. 2. The land gravel and sand collected by removing the topsoil from the fields on the former riverbed contains a lot of mud and requires thorough washing. Furthermore, it often contains light materials such as wood chips, tree roots, branches, and leaves, which must be removed by sorting appropriately. 3. Mountain gravel and sand collected from the gravel layers of hills formed by the uplift of old riverbeds or seabeds also contain a lot of mud and require thorough washing. They may also contain light materials such as pumice and shell fragments, which must be removed by sorting. 4. Recently, gravel and sand have been extracted from the dredged soil generated during dredging work on rivers and dams, and are being put to effective use. However, dredged soil often contains light materials, particularly wood chips, tree roots, branches, and leaves, which must be properly sorted and removed.

[0004] In the past, classifiers and dewaterers such as those described in Patent Document 1 have been widely used in aggregate production facilities. However, as mentioned above, there are various characteristics depending on the location where the raw materials are collected, and in order to stably produce high-quality aggregate from raw materials that contain a lot of mud (silt, clay, etc.) and light specific gravity materials, it has often been necessary to perform pretreatment using a classification tank or a specific gravity separator such as those described in Patent Document 2 before feeding the raw materials into the classifier and dewaterer.

[0005] The gravity separator of Patent Document 2 will be described in detail below. The main body has a supply port in the center of its top surface for receiving raw water, and an overflow weir and a gutter around the periphery of the main body for discharging mud and light-gravity materials together with excess water. The main body also has an under-discharge port on its bottom surface for discharging particles that have settled inside the main body together with water. Some of the water from the supply port is also discharged from the under discharge port, but the excess water that cannot be discharged from the under discharge port rises inside the main body and overflows from the overflow weir. In this way, the discharge amount from the under side and the discharge amount from the overflow side are balanced with the raw water supply amount, and operation continues.

[0006] Particles in raw water tend to settle within the main body at a speed close to the uniform settling velocity represented by Stokes' law according to their particle size, but are affected by the upward flow velocity due to overflow. Particles whose uniform settling velocity is significantly faster than the upward flow velocity tend to settle. Conversely, particles whose uniform settling velocity is equal to or slower than the upward flow velocity are pushed up by the upward flow and are likely to be expelled from the machine via overflow.

[0007] Furthermore, light-density materials such as wood chips, tree roots, branches, and leaves have already absorbed sufficient moisture and rarely float to the surface of the water, but tend to sink. However, because these light-density materials have a lower density than aggregate, they are pushed up by the rising current and are more likely to be discharged from the overflow side.

[0008] As described above, in the device of Patent Document 2, the discharge from the overflow side contains a large amount of mud and light specific gravity materials, while the discharge from the underside contains a large amount of particles such as sand. The amount of mud and light specific gravity materials mixed into the underside is reduced. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Publication No. 62-258762 [Patent Document 2] Publication number 04-040744 Summary of the Invention [Problem to be solved by the invention]

[0010] However, even with the gravity separator of Patent Document 2, some mud or light particles may get mixed into the underflow side, or some good quality particles may flow out to the overflow side, leaving room for improvement in classification and separation accuracy. This issue is not limited to gravity separators for aggregate production such as those in Patent Document 2, but also applies to equipment in the rare metal recycling field mentioned above and other fields. In other words, it is an issue common to equipment that separates solids from liquid.

[0011] When this issue was examined using the device described in Patent Document 2 as an example, the direction in which raw water is introduced into the main body is opposite to the direction in which excess water rises. Furthermore, as particles are discharged to the underside, some of the raw water is also discharged from the underside, resulting in a downward flow within the main body. Focusing on the movement of water within the main body, the introduced water forms an unstable boundary within the main body where it splits into a flow toward the underside (downward flow) and a flow toward the overflow side (upward flow), making the flow prone to turbulence. When particles near this boundary are caught in either flow, they move in that direction and are discharged, regardless of particle size. In particular, mud and light-gravity materials, which should ideally overflow, are highly likely to be discharged from the underside if they are affected by the downward flow.

[0012] Furthermore, in the device of Patent Document 2, the state of the underside discharge (solid-liquid ratio) is greatly affected by and fluctuates with the state of the supplied raw water (solid-liquid ratio). Fluctuations in the amount of water in the underside discharge also cause fluctuations in the amount of overflow water. In other words, this is a factor that makes it difficult to stabilize the upward flow rate. For this reason, even if the amount of raw water is increased to reduce the amount of mud and light-weight materials entering the underside (by increasing the upward flow rate and allowing as much mud and light-weight materials to overflow as possible), it is difficult to obtain an ideal, stable upward flow. Conversely, this increases the likelihood that good particles will be caught in the upward flow and flow out the overflow side, limiting the extent to which mud and light-weight materials can be reduced in the underside.

[0013] In addition, in the device of Patent Document 2, the flow of raw water and overflow wastewater is separated at the top by an inner cylinder. Raw water introduced from above into the inner cylinder flows toward the inner wall of the outer cylinder along an umbrella-shaped guide plate installed at the bottom of the inner cylinder, and it is expected that mud and foreign matter carried along this flow will reverse on the inner wall surface of the outer cylinder, rise between the outer and inner cylinders, and overflow. However, because water is viscous and contains many particles, mud and foreign matter are easily caught in the water and particles. Such mud and foreign matter cannot rise smoothly and instead flows downward through the gap between the inner wall of the outer cylinder and the umbrella-shaped guide plate. Furthermore, the precipitated particles are not aligned by particle size, but are a mixture of particles of various sizes, and their density is uneven. When a group of such mixed particles falls along the umbrella-shaped guide plate and through the gap between it and the inner wall of the outer cylinder, they are likely to get caught up in surrounding mud and foreign matter. These are hurdles to improving the classification and separation accuracy of the device of Patent Document 2.

[0014] An object of the present invention is to improve classification or separation accuracy in an apparatus for separating solids from a liquid compared to conventional apparatuses. [Means for solving the problem]

[0015] That is, the device for separating solids in a liquid according to the present invention comprises: a main body having a cylindrical internal space; an inner cylinder provided at the center of the internal space; a treatment object supply unit that supplies a liquid containing solids so that the liquid circulates along a side wall of the internal space, the inner cylinder is provided so that the liquid in the internal space falls into the inner cylinder over an overflow weir at the upper end of the inner cylinder and is discharged to the outside of the main body through an overflow discharge path connected to the lower end of the inner cylinder, an adjusting liquid supply port for supplying a liquid for adjusting a settling state of the solid content is provided on a side wall of the internal space at a position lower than a height at which the liquid containing the solid content is supplied; The inner space is characterized in that a sediment discharge port is provided at the lower end thereof for discharging settled solids together with a portion of the liquid in the inner space.

[0016] According to the configuration of the present invention, an adjusting liquid supply port is provided in the cylindrical internal space of the main body, so that the internal space can be previously filled with "liquid for adjusting the settling state of solids" and the adjusting liquid can be replenished during processing. Since the "liquid containing solids" to be processed is supplied above the adjusting liquid supply port, the probability of the "adjusting liquid" being present in the lower part of the internal space during processing is high, and a swirling flow of the "liquid containing solids" is formed mainly in the upper part of the internal space. The supplied "liquid containing solids" forms a swirling flow in the upper part of the internal space, and the liquid surface of the swirling flow reaches the top of the inner cylinder. The solids settle at a settling speed according to their size. Lighter solids do not settle, but instead, together with the swirling liquid, pass over the overflow weir at the top of the inner cylinder and are discharged through the interior of the inner cylinder. The settling solids pass through the area below the internal space where there is a large amount of "liquid for adjustment" and reach the bottom, where they are discharged from the sediment discharge port together with the liquid in the internal space. In this way, by supplying an "adjustment liquid" separately from the "liquid containing solids" to the internal space and forming a swirling flow of the "liquid containing solids" above the internal space, an unstable boundary surface between the ascending and descending flows of the "liquid containing solids" is no longer formed in the internal space, preventing solids that are desired to settle from being caught up in the flow of overflowing liquid. Furthermore, it is also possible to prevent light-density solids that are not desired to settle from being caught up in the flow of descending liquid. This allows for improved classification or separation accuracy compared to conventional methods. Furthermore, even if the solid-liquid ratio of the "liquid containing solids" to be treated fluctuates, by supplying the "adjustment liquid" to the internal space, fluctuations in the liquid discharged from the sediment discharge outlet at the lower end of the internal space are suppressed, and fluctuations in the classification or separation accuracy of solids are unlikely to occur.

[0017] Preferably, the inner cylinder is provided with a detachable outer diameter adjusting member for adjusting the outer diameter of the inner cylinder. By changing the outer diameter of the inner cylinder using the outer diameter adjusting member, the settling state of solids in the internal space can be adjusted.

[0018] Preferably, the outer diameter adjustment member is frustoconical and attached to the outer periphery of the inner tube, with the outer diameter at the lower end being larger than the outer diameter at the upper end. This narrows the space between the sidewall of the inner space of the main body and the outer diameter adjustment member attached to the outer periphery of the inner tube. The excess adjustment liquid flows upward, but its upward flow rate is faster in the narrow lower space than in the wide upper space. Therefore, the resistance of the adjustment liquid to the solids settling in this space increases as they move downward, making it easier for undesired solids, such as mud or light-gravity materials, that adhere to or are caught up in the solids and descend to rise.

[0019] Furthermore, it is preferable that a supply amount adjusting device for the adjustment liquid be connected to the adjustment liquid supply port. It is preferable that the supply amount of the adjustment liquid be greater than the discharge amount of the liquid from the sediment discharge port. This can suppress the downward flow of the liquid containing solids supplied from above. Furthermore, the excess adjustment liquid rises and overflows and is discharged together with the liquid containing solids. By increasing or decreasing the upward flow of this excess adjustment liquid, the settling state of the solids can be adjusted. Furthermore, the upward flow of the excess adjustment liquid becomes an ideal upward flow in the internal space, and also serves to facilitate the overflow of solids that should not be settled, such as mud and light-gravity materials.

[0020] The supply unit for the material to be treated preferably includes a means for converting the potential energy of the liquid containing solids into swirling energy. This configuration has the advantage of suppressing the generation of turbulence and reducing the amount of power energy consumed, since it is not necessary to pump the liquid containing solids using a pump or the like as in a wet cyclone.

[0021] It is also preferable that a supply amount adjustment device for the liquid containing solids is connected to the treatment object supply section. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a vertical cross-sectional view showing the overall structure of a classifier according to an embodiment. [Figure 2] FIG. 2 is a cross-sectional view taken along a plane including a raw water inlet of the classifier. [Figure 3] FIG. 2 is a cross-sectional view of the classifier taken along a plane including an adjusted water supply port. [Figure 4] Images A to I are images of the internal space of the classifier observed from above, showing the process from the start of operation to when the process becomes stable in chronological order. [Figure 5] A schematic diagram showing the movement of particles, mud, and light-density materials in the internal space. [Figure 6] This is an image showing test results using fine sand. [Figure 7] This is an image showing the test results using private land sand. [Figure 8] This is an image showing the test results using crushed PET bottles. [Figure 9] This is an image showing the processing status of crushed PET bottles. DETAILED DESCRIPTION OF THE INVENTION

[0023] The device for separating solids from a liquid of the present invention can be applied to, for example, a classifier or a foreign matter removal device. Here, a classifier will be described as an example of one embodiment, using the drawings. The classifier 10 in FIG. 1 is a device that classifies particles contained in input raw water based on differences in sedimentation speed in the water. The classifier 10 is also a device that removes mud and light-weight substances contained in the raw water. The raw water to be treated is turbid water containing water, particles (such as sand), mud, and light-weight substances.

[0024] The overall configuration of the classifier 10 is roughly divided into a treatment object supply section 1, a main body 2, and an inner cylinder 3.

[0025] <Material supply section> The material supply unit 1 for treatment receives raw water at an elevated position and converts the potential energy of the raw water into rotational energy. It includes an annular supply hopper 11, an annular feed chamber 12, and four pipes 13 connecting the two. The bottom surface of the supply hopper 11 has four holes spaced equally along the annular circumference, each of which connects to four vertical pipes 13. The lower ends of the four pipes 13 are connected to the annular feed chamber 12 (see also FIG. 2). The inner diameter of the feed chamber 12 is the same as the inner diameter of the cylindrical internal space 21 of the main body 2 (described later). The internal space 21 of the main body 2 is connected below the feed chamber 12 so that their central axes coincide. The inner wall of the feed chamber 12 is provided with eight raw water inlets 14 spaced equally around the circumference. Each raw water inlet 14 is horizontal and faces the circumferential direction (i.e., the tangential direction) of the inner wall of the feed chamber 12, not the central axis of the feed chamber 12. In addition, guide plates 15 are provided on the annular bottom surface of the feed chamber 12 in front of each raw water inlet 14 so that raw water from the pipeline 13 is released from the raw water inlet 14 in the circumferential direction of the inner wall.

[0026] In this configuration of the material to be treated supply unit 1, when raw water is fed into the supply hopper 11, the raw water flows evenly from the supply hopper 11 into the four pipes 13 and forms a swirling flow inside the annular feed chamber 12. When the raw water is then released into the internal space 21 of the main body 2 from the eight raw water inlets 14 on the inner peripheral wall of the feed chamber 12, a swirling flow is also formed in the internal space 21. In this way, the potential energy of the raw water fed into the supply hopper 11 is converted into the swirling energy of the raw water in the internal space 21.

[0027] A pump for feeding raw water into the supply hopper 11 and a flow rate adjusting valve 4 are provided on the path upstream of the supply hopper 11 .

[0028] The treatment object supply unit 1 is not limited to this, and may be, for example, an inverted cone-shaped hopper. The raw water introduced from above may be made into a swirling flow in the inverted cone-shaped hopper, and the swirling flow may be allowed to flow from above into the internal space 21 of the main body 2. In either case, it is preferable to weaken the momentum of the raw water pressure-fed by a pump or the like before introducing it into the internal space 21.

[0029] <Main body> Next, the main body 2 is roughly composed of three annular blocks (upper adjustment water pipe block 22, lower adjustment water pipe block 23, and inverted cone-shaped overflow pipe block 24), which are connected in the vertical direction to form a cylindrical space 21 inside the main body 2 and an inverted cone-shaped internal space below it.

[0030] The upper and lower regulated water pipeline blocks 22, 23 are supplied with regulated water from the outside (which may be treated water as long as it does not contain solids) through dedicated pipelines from an upstream pump and flow control valve 5. The upper and lower regulated water pipeline blocks 22, 23 are connected via a flange-shaped upper-stage water passage plate 26 and packings.

[0031] The upper-stage water passage plate 26 is formed with a flow path for conditioned water, and conditioned water in the upper-stage conditioned water pipe block 22 passes through the flow path of the water passage plate 26 and is supplied to the internal space 21 from conditioned water supply ports 28. The water passage plate 26 has eight conditioned water supply ports 28 formed at equal intervals in the circumferential direction of the inner peripheral wall. These conditioned water supply ports 28 are all oriented horizontally, and may be oriented in the circumferential direction (i.e., tangential direction) of the inner peripheral wall of the water passage plate 26 as shown in FIG. 3(A), or may be oriented toward the central axis of the water passage plate 26 as shown in FIG. 3(B). In the case of FIG. 3(A), the conditioned water released into the internal space 21 forms a swirling flow along the outer periphery of the inner cylinder 3 in the same direction as the swirling flow of the raw water.

[0032] The lower water passage plate 27 is configured similarly to the upper water passage plate 26, and is sandwiched between the lower regulated water pipe block 23 and the inverted cone-shaped overflow pipe block 24. As such, the upper and lower water passage plates 26, 27 are flange-shaped and detachable, so they can be easily replaced with plates of different thicknesses, and the shape of the regulated water flow path (discharge direction, flow rate, etc.) can be easily changed.

[0033] A sediment discharge port 29 is provided at the lower end of the inverted cone-shaped overflow pipe block 24 for discharging particles that have settled out of the internal space 21 together with water. If a check valve 6 made of, for example, rubber is attached to the sediment discharge port 29, the check valve 6 will automatically open due to the weight of the particles accumulated in the sediment discharge port 29, allowing the settled particles to be intermittently discharged together with water.

[0034] <Inner cylinder> The inner cylinder 3 is provided in the internal space 21 of the main body 2, and coincides with the central axis of the cylindrical internal space 21. The upper end of the inner cylinder 3 is open, forming an overflow weir 31 for water in the internal space 21. The lower end of the inner cylinder 3 communicates with four-way overflow discharge channels 7, and the end of the overflow discharge channels 7 is connected to the channels of an inverted cone-shaped overflow pipe block 24. The relationship between the height of the raw water inlet 14 and the height of the overflow weir 31 of the inner cylinder 3 can be set as appropriate. In Figure 1, the overflow weir 31 is higher than the raw water inlet 14, but it may be at the same level or lower.

[0035] In this way, when the water in the internal space 21 exceeds the overflow weir 31, it falls into the interior of the inner cylinder 3 together with the mud and light-gravity substances contained in the raw water, and is discharged to the outside of the main body 2 through the overflow discharge path 7 and the inverted cone-shaped overflow pipe block 24. As with the number of the aforementioned pipelines 13 (4 lines), raw water inlets 14 (8 locations), and adjusted water supply outlets 28 (8 locations x 2 stages), the number of the above-mentioned overflow discharge paths 7 is merely an example, and the number, size, thickness, etc. of these are set according to the respective treatment flow rates.

[0036] <Classification process> An example of the operation of the classifier 10 of this embodiment will be described using the time-series images A to I in Figure 4. Here, a case is shown in which the adjusted water forms a swirling flow around the outer periphery of the inner cylinder 3. First, only the adjusted water is supplied from the two adjusted water supply ports 28, one above the other. Image A shows the state immediately after the supply of adjusted water begins. On the side wall surface of the internal space 21, the positions of the raw water inlet 14, the upper adjusted water supply port 28, and the lower adjusted water supply port 28 can be observed, from top to bottom. Image B shows the state in which the level of adjusted water is rising in the space around the outer periphery of the inner cylinder 3.

[0037] Image C shows the state immediately after the release of raw water (turbid liquid) began. It can be seen that a swirling flow of raw water immediately forms around the upper outer periphery of the inner cylinder 3. Images D and E show that the swirling flow of raw water gradually increases, and the water level continues to rise. Image F shows the state when the water level has reached the overflow weir 31, and image G shows the state immediately after the overflow has started. Image H shows the state when the water level has risen further and the overflow amount has increased. In image I, the swirling flow of raw water on the upper outer periphery of the inner cylinder 3 has stabilized, and the classification process has become stable.

[0038] As shown in the schematic diagram of the longitudinal cross section in Figure 5(A), an adjusted water supply port 28 is provided in the internal space, allowing adjusted water to be stored in advance in the internal space and to be replenished with adjusted water during treatment. Because the raw water inlet 14 is located above the adjusted water supply port 28, the probability of adjusted water being present in the lower part of the internal space during treatment is high, and a swirling flow of raw water is formed mainly in the upper part of the internal space. The supplied raw water forms a swirling flow in the upper part of the internal space, and the water surface of the swirling flow reaches the upper end of the inner cylinder 3. Due to the action of centrifugal force, the water level on the inner cylinder 3 side is low and the water level on the side wall side of the internal space is high, resulting in an inclined water surface as shown in Figure 5(A).

[0039] In the classifier of this embodiment, the inner cylinder 3 is located inside the internal space, and overflowing water falls into the inner cylinder 3. In the conventional device of Patent Document 2, the water overflows outside the internal space. It can be seen that the length of the overflow weir is shorter when the water overflows into the inner cylinder 3, as in this embodiment. Therefore, when comparing the two under the same overflow amount, the water level from the overflow weir to the water surface is higher in this embodiment, making it easier for mud and light-gravity materials contained in the raw water to overflow. The inclination of the water surface toward the overflow weir also helps to prevent mud and light-gravity materials from getting caught in the overflow weir and to overflow smoothly in a short time.

[0040] On the other hand, particles in the raw water settle at a settling speed according to their size, as shown in Figure 5(A). The settling particles pass through the region where there is a lot of conditioned water from the middle to the bottom of the internal space, reaching the bottom and are discharged from the sediment discharge port 29 together with the water in the internal space. As the particles pass through the region where conditioned water is dominant, light specific gravity substances attached to or mixed in the particles are easily removed (a cleaning effect is achieved for the settling particles). In addition, the water discharged from the sediment discharge port 29 is mainly conditioned water, which reduces the amount of water supplied from above that is discharged from the sediment discharge port 29.

[0041] In this way, by supplying conditioned water separately from the raw water to the internal space and forming a swirling flow of raw water above the internal space, an unstable boundary surface between the ascending and descending flows of raw water is no longer formed in the internal space, preventing particles that are intended to settle from being caught up in the overflow flow. This also prevents mud and light-gravity materials that are not intended to settle from being caught up in the descending flow. This results in improved classification or separation accuracy compared to conventional methods.

[0042] Furthermore, in the device of Patent Document 2, raw water is directly introduced from the upper center of the main body as a mixture of particles and water, which significantly disturbs the solid-liquid ratio and other conditions of the raw water introduced into the device, affecting the accuracy of separation and classification. To stabilize the disturbances at the time of introduction, it is necessary to increase the water depth and volume of the main body, which results in a larger size. In contrast, in the classifier of this embodiment, as shown in Figure 5(B), raw water is introduced from the annular feed chamber through the raw water inlet 14 into the internal space in a horizontal direction, swirling along the sidewall. The raw water merges with the raw water inside the main body near the water surface, causing the incoming raw water to fan out horizontally. In this way, particles in the raw water are evenly dispersed within the feed chamber and introduced into the internal space. Furthermore, centrifugal force during inflow biases particles toward the sidewall of the internal space, biasing mud and light-gravity particles toward the central axis of the internal space. Furthermore, because the inner cylinder 3, which forms the overflow weir, is located within the internal space, water containing mud and light-gravity particles biased toward the central axis selectively overflows the weir and falls into the interior of the inner cylinder 3. This minimizes turbulence during raw water introduction into the internal space, improving classification and separation accuracy within a compact main body.

[0043] Furthermore, even if the solid-liquid ratio of the raw water fluctuates, by supplying adjusted water to the internal space 21, fluctuations in the water discharged from the sediment discharge outlet 29 at the lower end of the internal space 21 are suppressed, making it less likely that fluctuations will occur in classification or separation accuracy.

[0044] Furthermore, in the classifier 10 of this embodiment, it is preferable to operate the supply rate adjustment valve 5 so that the amount of adjustment water supplied is greater than the amount of water discharged from the sediment discharge port 29. This makes it possible to suppress the downward flow of raw water from above. Furthermore, since excess adjustment water rises and is discharged from the overflow side, the settling state of particles can be adjusted by increasing or decreasing the upward flow of this excess adjustment water. Furthermore, the upward flow of the excess adjustment water becomes an ideal upward flow in the internal space, making it easier for solids that should not be settled, such as mud and light-weight materials, to overflow.

[0045] <Adjustment cone> The adjusting cone 8 shown by the chain line in Fig. 1 will now be described. The adjusting cone 8 is a member for adjusting the outer diameter of the inner cylinder 3, and is detachably provided in the internal space 21. The necessary sizes for the inner diameter of the internal space 21 and the outer diameter of the inner cylinder 3 are determined based on the conditions of use of the classifier, while the role of the adjusting cone 3 is to adjust the classification and separation state.

[0046] The adjustment cone 8 is a truncated cone provided on the outer periphery of the inner cylinder 3, with the outer diameter of the lower part being larger than that of the upper part. As a result, the space between the side wall surface of the internal space 21 and the adjustment cone 8 becomes narrower as it goes downward. The excess adjustment water released into the internal space 21 flows upward, but the presence of the adjustment cone 8 makes the excess adjustment water rise faster in the narrow lower space than in the wide upper space. For particles settling in this space, the resistance of the adjustment water increases as they go downward, making it easier for solids that do not want to settle, such as mud or light-specific-gravity materials, that have adhered to or been caught up in the particles and are descending, to rise.

[0047] The adjusting cone 8 can have a variety of shapes. For example, adjusting cones 8 with different taper angles and heights can be selected as appropriate. Even under the same conditions of releasing the adjusted water, the speed at which the excess adjusted water rises can be changed by selecting the adjusting cone 8, and the classification and separation state of the classifier 10 can be adjusted.

[0048] <Bubble water> In the classifier 10 of this embodiment, a bubble water outlet for discharging bubble water into the internal space 21 can be provided to provide the functions of cleaning settling particles and promoting floating. For example, the conditioned water supply port 28 of the lower water passage plate 27 in FIG. 1 may be used as the bubble water outlet. This is indicated by "A" in FIG. 1. In this case, bubble water from a bubble water generator may be supplied to the lower conditioned water pipe block 23 instead of conditioned water. Alternatively, the bubble water outlet may be provided at the bottom of the inner cylinder 3, at the position indicated by the black circle "B" in FIG. 1, or immediately before the sediment discharge port 28, at the position indicated by the black circle "C" in FIG. 1.

[0049] The bubble water can be water containing tiny bubbles called microbubbles with a diameter of 1 to 100 μm, but is not limited to microbubble water and can also be water with fine bubbles of 1 mm or less. The size of the bubbles in the bubble water can be adjusted by adjusting the amount of air intake in the bubble water generator.

[0050] The smaller the bubbles in bubble water are, like microbubbles, the slower their floating speed and the less effective they are at floating solids. However, tiny bubbles carry a negative charge in water, which means they attract positively charged substances (dirt and foreign matter) in the raw water and are easily adsorbed to these substances. They can also penetrate tiny gaps that water cannot penetrate, and adsorb substances in those gaps. In the classifier 10 of this embodiment, if microbubble water, for example, is introduced into an area where adjusted water is dominant, the microbubbles will adsorb to the mud and light-density materials adhering to or entrained in the settling particles. After adsorption, the microbubbles contract and eventually collapse (collapse). At this time, energy is generated locally, making it easier to separate the mud and light-density materials from the particles (cleaning effect of bubble water). The separated mud and light-density materials rise together with the microbubble water and adjusted water and are discharged to the overflow side.

[0051] Flotation is also known as a separation technology that uses bubbled water. Flotation generally uses bubbles larger than microbubbles. The bubbles in the bubbled water adhere to hydrophobic (difficult to wet) substances and cause them to float up, allowing them to be separated from hydrophilic (easily wet) substances that remain in the liquid. In flotation, it is believed that bubbles in the bubbled water adhere to hydrophobic materials by directly colliding with them, but the classifier 10 of this embodiment can more reliably cause bubbles in the bubbled water to adhere to materials such as light-density materials through the following characteristic action. In an environment where many fine bubbles are generated, these fine bubbles are said to form and grow particularly in cracks and hydrophobic areas of particles. Therefore, in an environment where bubble water and light-gravity materials are mixed, as in this embodiment, cracks and depressions are prominently present on the surface of the light-gravity materials, and fine bubbles are likely to form and grow in these cracks and depressions, thereby increasing the effect of flotation on the light-gravity materials (the floating promotion effect of bubble water). This effect is not limited to relatively large bubbles; even tiny bubbles with weak buoyancy, such as microbubbles, can achieve the floating promotion effect if they enter cracks and depressions in large numbers and grow. The use of bubbled water also has the effect of reducing the amount of water put into the interior space.

[0052] <Test result 1> The classifier of this embodiment was used to process "fine sand" and "private land sand." Images of the exterior of the containers containing the raw water and the container containing the collected material (a mixture of sediment and water) from the sediment discharge outlet are shown in Figures 6 and 7. These images were taken immediately after the containers were thoroughly shaken simultaneously.

[0053] The raw water containing fine sand (Figure 6(A)) was fed into the classifier at a rate of 120 L / min. For comparison, Figure 6(B) shows the recovered product processed without any adjustment water. The turbidity of the supernatant water was almost the same as that of the raw water. Next, the recovered product after treatment with the adjusted water supply rate set at 40 L / min is shown in Figure 6(C). The supernatant water was less turbid than the raw water. Furthermore, the recovered product after treatment with the adjusted water supply rate set at 80 L / min is shown in Figure 6(D). The turbidity of the supernatant water was significantly lighter than that of the raw water. In this way, the turbidity of the supernatant water improved depending on the amount of conditioned water supplied. It was found that the use of conditioned water is effective in separating mud and other components from the raw water.

[0054] Similarly, raw water from residential sand (Figure 7(A)) was fed into the classifier. For comparison, raw water from residential sand was fed into the classifier at a supply rate of 80 L / min, and the recovered product was treated under conditions of zero adjustment water, as shown in Figure 7(B). Furthermore, raw water from residential sand was fed into the classifier at a supply rate of 120 L / min, and the recovered product was treated under conditions of zero adjustment water, as shown in Figure 7(C). Even when the supply rate of raw water was changed, the turbidity of the supernatant water remained almost the same as the raw water. Next, the raw water supply rate for private land sand was set at 120 L / min, and the adjusted water supply rate was set at 20, 40, 60, and 80 L / min. The recovered samples were treated at these four rates, shown in Figures 7(D), (E), (F), and (G). The turbidity of the supernatant water was improved compared to the raw water in all cases, and became thinner as the amount of adjusted water supplied increased. In this way, the turbidity of the supernatant water gradually improved depending on the amount of conditioned water supplied, and it was found that the use of conditioned water is effective in separating mud and other components from the raw water.

[0055] <Test result 2> The classifier of this embodiment was used to process "crushed PET bottles." The appearances of the raw material crushed PET bottles (Fig. 8(A)), the separated product from the overflow (Fig. 8(B)), and the separated product from the sediment discharge port (Fig. 8(C)) are shown.

[0056] The crushed bodies of PET bottles are called PET flakes. As shown in Figure 8(A), the raw material contains many crushed caps and films in the PET flakes. With conventional equipment, crushed labels and caps often adhere to the PET flakes, making separation difficult. In contrast, the classifier of this embodiment can separate only the PET flakes by sedimentation, as shown in Figure 8(C), and separate the crushed caps and films by overflow, as shown in Figure 8(B), improving the accuracy of separating crushed PET bottles. Figure 9 shows an image of treated water containing crushed PET bottles being treated using a test machine with the same configuration as the classifier of this embodiment. It shows that crushed caps and film separated from the PET flakes gather on the surface of the swirling water at the top of the internal space, then quickly overflow and fall into the inner tube.

[0057] <Application to rare metal recycling> The classifier of this embodiment can also be applied to a device for removing dissolved residue from a mixture of metal eluate and dissolved residue after dissolving metals contained in crushed materials such as electronic circuit boards with an acid or alkaline solution, or for removing precipitated sediment from the metal eluate. A mixture of the metal eluate and dissolved residue is fed into the classifier. While an acid or alkaline solution can be used as the adjustment liquid, water has the advantage of being easier to handle. In the classifier, the metal eluate is collected from the overflow side, and the dissolved residue settles and is discharged from the sediment outlet.

[0058] Although one embodiment of the present invention has been described above, the device for separating solids from a liquid of the present invention can also be fully applied to devices for other purposes, such as foreign matter removal devices. Furthermore, the liquid to be added together with the solids is not limited to water as in this embodiment, but can be a liquid such as oil, as needed. The adjusting liquid is also not limited to water, but can be selected appropriately depending on the liquid contained in the material to be treated. [Explanation of symbols]

[0059] 1. Processing object supply section 2 Main unit 3 Inner cylinder 4. Raw water supply rate adjustment valve (a device for adjusting the supply rate of liquids containing solids) 5. Adjustment water supply rate adjustment valve (adjustment liquid supply rate adjustment device) 6. Check valve 7 Overflow discharge channel 8 Adjustment cone (outer diameter adjustment part) 10. Classifier (a device that separates solids from liquid) 11 Supply hopper 12 Feed chamber 13 Conduit 14 Raw water inlet 15 Guide plate 21 Interior Space 28 Adjusted water supply port (adjusted liquid supply port) 29 Sediment outlet 31 Overflow Weir

Claims

1. An apparatus for separating solids from a liquid, comprising: a main body having a cylindrical internal space; an inner cylinder provided at the center of the internal space; a treatment object supply unit that supplies a liquid containing solids so that the liquid circulates along a side wall of the internal space, the inner cylinder is provided so that the liquid in the internal space falls into the inner cylinder over an overflow weir at the upper end of the inner cylinder and is discharged to the outside of the main body through an overflow discharge path connected to the lower end of the inner cylinder, an adjusting liquid supply port for supplying a liquid for adjusting a settling state of the solid content is provided on a side wall of the internal space at a position lower than a height at which the liquid containing the solid content is supplied; A sediment discharge port is provided at the lower end of the internal space to discharge settled solids together with a portion of the liquid in the internal space. An apparatus for separating solids from a liquid, comprising:

2. 2. The apparatus for separating solids in a liquid according to claim 1, wherein an outer diameter adjusting member for adjusting the outer diameter of said inner cylinder is detachably provided on said inner cylinder.

3. 3. The apparatus for separating solids in a liquid according to claim 2, wherein the outer diameter adjustment member is a truncated cone provided on the outer periphery of the inner cylinder, and is formed so that the outer diameter of the lower part of the inner cylinder is larger than the outer diameter of the upper part.

4. 2. The apparatus for separating solids contained in a liquid according to claim 1, wherein a supply amount adjusting device for adjusting the amount of the adjusting liquid is connected to said adjusting liquid supply port.

5. 2. An apparatus for separating solids in a liquid according to claim 1, wherein the supply unit for the material to be treated includes means for converting potential energy of the liquid containing the solids into rotational energy.

6. 2. The apparatus for separating solids in a liquid according to claim 1, wherein a supply amount adjustment device for the liquid containing solids is connected to the treatment object supply section.

Images