CN1970160B - Filtering device - Google Patents

Abstract

A screening device is provided, which does not reduce the recovery rate of heavy specific gravity objects, and prevents medium light specific gravity objects from mixing with heavy specific gravity objects. It is provided with an upflow generation pipe (8) for generating upflow in the water tank (2), and a suction pipe (9) for attracting the medium-light specific gravity objects (B) floating under the water surface by means of the upflow to the upper side , so that the medium-light specific gravity (B) with a slow deposition rate is floated under the water surface by upflow, and is sucked and discharged into the suction pipe (9), thereby preventing it from being mixed with the heavy substance that sinks to the bottom of the water tank (2). In the specific gravity (A), and even if the heavy specific gravity (A) enters the suction pipe (9) due to the upflow, it will not be attracted by the suction pipe (9) to the top but sink to the outside, and will not Lowering the recovery rate of the heavy specific gravity (A) can prevent the medium light specific gravity (B) from being mixed into the heavy specific gravity (A).

Description

Screening device

technical field

The invention relates to a wet type screening device which utilizes the specific gravity difference to screen a mixture in a water tank. the

Background technique

As a screening device for a mixture using a difference in specific gravity, a wet type screening device that floats and sinks a mixture in a water tank due to a difference in specific gravity is used in various fields. the

This kind of wet screening device is used in the following fields, for example, when obtaining sawdust as a raw material for papermaking, from a mixture of heavy objects such as gravel and iron flakes, and separating the heavy objects as foreign objects. Sawdust with a specific gravity greater than 1 can be efficiently recovered, and a conveyor belt (conveyor) is installed in the water tank, and the water in the tank is sucked from the back of the conveyor belt, and supplied to the tank where the heavy specific gravity is deposited. The bottom of the vertical cylinder generates an upflow in the vertical cylinder, and pushes back the wood chips of medium and light weight objects deposited in the vertical cylinder by the upflow, and picks them up with a conveyor belt (refer to Patent Document 1). the

[Patent Document 1] JP-A-62-79858 Gazette

In addition, in the field of waste treatment, aggregates of heavy objects having a specific gravity of 2.5 or more are collected from concrete (concrete), which is construction waste, and are reused. Plastic chips, wood chips, and the like are mixed in this recycled aggregate. In the plastic sheet in this mixture, there are mixed with polypropylene resin (polypropylene resin) and polyethylene resin (polyethylene resin) and other light specific gravity materials with a specific gravity ratio of 1, and vinyl chloride resin (vinyl chloride resin) with a specific gravity ratio of 1. Large medium to light specific gravity. In addition, the specific gravity of wet wood chips is higher than 1, and it is mixed therein as medium-light specific gravity. If a wet screening device is used to screen aggregates from a mixture mixed with such medium-light specific gravity materials, there will be a problem that the sinking medium-light specific gravity materials will be mixed into the aggregates, which will deteriorate the screening accuracy of the aggregates. the

In addition, in the flying target shooting range, it is necessary to recover the lead shotgun scattered on the soil site. From the mixture of soil and shotgun recovery, the shotgun is used as a heavy specific gravity, and the soil is used as a medium-light specific gravity. Screen shotguns with precision.

In the processing field of the above-mentioned wastes and shooting ranges, etc., when using a wet screening device to screen heavy specific gravity objects from mixtures, in order to prevent medium light specific gravity objects with a specific gravity larger than 1 from being mixed into heavy specific gravity objects, as described in Patent Document 1, consider The method adopted is to use the rising water to push back the sinking medium-light specific gravity objects and pick them up by the conveyor belt. If the raised heavy specific gravity is not returned to the water tank, there is a problem that the recovery rate of the heavy specific gravity is lowered. the

Therefore, the object of the present invention is to prevent the medium-light specific gravity from being mixed into the heavy specific gravity without lowering the recovery rate of the heavy specific gravity. the

Contents of the invention

In order to solve the above-mentioned problems, the present invention uses the suction pipe to suck and remove the medium-heavy objects floating by the upflow, and at the same time, utilizes its own weight to sink the heavy objects entering the suction pipe and return them to the water tank. the

Accordingly, since the heavy objects are returned to the water tank without being attracted, the heavy objects sunk in the water tank may be collected as before. the

The composition of this invention is a screening device, which puts the mixture to be screened into the water tank, and uses the difference in specific gravity to screen the heavy specific gravity in the mixture that sinks to the bottom of the tank, wherein, in the water tank, set There is an upflow generation pipe for generating upflow, and a suction pipe for attracting floating objects floating in water due to the upflow from the downward opening to the top, and the suction force of the suction pipe is set so that even if the The heavy specific gravity will also make it sink by its own weight when it enters the suction tube. the

The suction force of the suction pipe is determined by the flow cross-sectional area of the suction pipe, the suction flow rate, the capacity of the suction pump, etc., so they should be set appropriately through experiments and actual work so that even heavy objects can enter the suction pipe. , will also make it sink by its own weight. the

For example, if the suction flow rate of the suction tube is slower than the flow rate of the upward flow, the mixture containing the heavy specific gravity rises through the upward flow. The specific gravity sinks to the bottom of the suction tube due to its own weight. That is, because the suction flow velocity is slower than the flow velocity of the upflow, heavy objects raised by the strong upflow will not be sucked in by the weak suction flow, but will sink to the bottom of the suction pipe by their own weight, enabling high-precision filter. the

As a method of making the suction flow velocity slower than the flow velocity of the upward flow, for example, it is conceivable to make the opening area of the upward flow generation pipe larger than the flow cross section of the inlet portion of the suction pipe that is sucked upward from the opening of the suction pipe. The area is small and so on. If the opening area (flow cross-sectional area) is made different in this way, usually a strong upward flow flows out from the opening of the upward flow generating tube, so the mixture containing heavy specific gravity may rise together with the upward flow and enter the suction tube. However, during the suction process, because the suction flow rate is slower than the ascending flow rate, the heavy specific gravity will not be further sucked into the suction tube, but will sink to the bottom of the suction tube by its own weight. This difference in flow cross-sectional area is effective when the same flow rate flows through the upflow generating tube and the suction tube. the

The length of the inlet portion of the suction tube is appropriately set (see L in FIG. 2 ) in consideration of the flow rate and the like based on experiments such as experiments in which heavy specific gravity objects entering the inlet portion sink smoothly by their own weight. the

As long as the opening of the upflow generating pipe is the position where the upflow is generated in the water tank, any place in the water tank is fine, but the mixture to be thrown into the water tank by the upflow should be appropriately set according to experiments, actual operations, etc. Smooth floating position. the

The positional relationship between the opening of the upflow generation tube and the opening of the suction tube is set according to experiments, actual operations, etc., so that the two openings have an appropriate distance and angle to face each other, so that the upflow can be successfully sucked and floated in the water. of floating objects. In this case, it is preferable to form a positional relationship in which all of the mixture except the heavy specific gravity is attracted and only a part of the heavy specific gravity is attracted. the

In this structure, along the flow direction of the mixture, for example, a vertical partition plate is used to divide the inside of the water tank into several rows, and the suction pipes are respectively arranged on each of the partitioned rows. the

If so, because the upflow through the partition plate is rectified, the medium and light specific gravity objects can be stably floated. the

At this time, the size classification of the mixture put into the water tank is carried out in advance with a sieve, and the sized mixture is put into each of the separated rows, thereby improving the screening accuracy with the predetermined specific gravity as the branch point. . That is, if the size of the mixture is the same, the buoyancy of the mixture through the upwelling is roughly equal, and due to the difference in the sinking force of its own weight caused by the difference in specific gravity, the medium light specific gravity is easy to rise, and the heavy specific gravity will easily sink. the

In addition, the buoyancy force on smaller objects is smaller, but because the sinking force brought by their own weight is greatly reduced, so when the size classification is not performed, the small-sized heavy specific gravity may be compared with its larger size but specific gravity The small mixture is sucked together by the suction pipe and discharged to the outside.

Therefore, if the size classification is carried out, the strength of the upwelling of each column can be changed, and only the heavy specific gravity and the medium light specific gravity of each size are separated to the sinking side and the rising side according to the difference in specific gravity, so as to reduce the above-mentioned differences in size. influence and improve the screening accuracy. the

In addition, the upflow may be generated by one upflow generating tube, or upflow generating tubes may be provided in each of the separated columns, or upflow generating tubes may be provided in each of more than two columns. In the latter case, the opening of one upflow generating tube faces two or more rows. the

A plurality of suction pipes may be sequentially arranged toward the flow direction of the mixture. If so, the suction force of the suction pipe is gradually increased (intensified) toward the flow direction of the mixture, that is, the suction force of the suction pipe on the downstream side is higher than that of the upstream side of the mixture flow. The specific gravity of the attracted (captured) object can filter and capture substances with different specific gravity. The number of suction tubes is appropriately set according to the number of captured objects having poor specific gravity. the

At this time, each of the suction pipes is provided with upflow generation tubes respectively, and the setting method is to face the flow direction of the mixture, so that the upflow caused by each upflow generation tube is sequentially strengthened (the upflow velocity is sequentially increased), This enables smooth floating and suction according to the specific gravity of the captured object. the

For example, when two upward flow generation pipes are provided, the suction pipe on the front side (the upstream side of the flow of the mixture) sucks medium-light objects such as plastics with a specific gravity larger than 1, and then the suction pipe on the rear side sucks untreated objects. The heavy objects such as aggregates that are attracted to the heavy objects in the suction pipe on the front side have a relatively small specific gravity, and the following three types can be screened out: iron, copper, and lead that are not attracted by the suction pipes on the front side Metals such as heavy specific gravity objects with very large specific gravity; heavy specific gravity objects such as aggregates that are attracted by the suction pipe on the rear side with relatively small specific gravity; medium light specific gravity objects that are attracted by the suction pipe on the front side. the

In addition, even if the suction force of each suction tube is not changed, the rear side suction tube can suck the floating matter that is not sucked by the front side suction tube, so the screening accuracy can be improved. the

In addition, if the upward flow generating tubes are provided for the respective suction tubes, the mixture can be smoothly floated and sent into the respective suction tubes, and the screening accuracy can be further improved. the

In this case, regarding the positional relationship between the opening of the upward flow generation tube and the opening of the suction tube, the two openings are set to face each other at an appropriate distance and angle in experiments, actual operations, etc., so that the specific gravity required for suction is as small as possible. Objects that can successfully attract floating objects of the required specific gravity that float in the water due to upwelling. the

If the openings of the upflow generating tube and the suction tube are made to be in the shape of long holes in the transverse direction (not only including ellipse, but also rectangular. Referring to Fig. 14 ) with respect to the flow direction of the mixture, the upflow The narrowing of the width in the water tank produces a clear flow, and since the suction flow also narrows in the flow direction of the mixture, the suction effect also becomes sure. the

The length of the long hole is appropriately set according to the length in the lateral direction relative to the flow direction of the mixture and the width of the water tank. In addition, the width of the long hole is also appropriately set in consideration of the degree of formation and attraction of the upwelling. the

In these structures, between the upward flow generation pipe and the suction pipe in the water tank, an inclined screen with the lower end side opened as a discharge end is provided toward the flow direction of the mixture, and is directed toward the flow direction of the mixture. It is inclined downward, and the mixture is put into the upper end side of the inclined screen, so that the heavy specific gravity can sink from the discharge end on the lower end side to the bottom of the water tank. the

If so, on the inclined screen, because the mixture that sinks in a group state is disturbed by the upflow and floats up, the medium and light specific gravity is smoothly separated, and at the same time, the heavy specific gravity directly falls on this screen and sinks to the water tank. end. That is, the separation of the medium light specific gravity and the heavy specific gravity becomes smooth, and because the mixture that sinks in this group state can hit the upwelling, so the amount (water amount) of the upwelling can be reduced (it can be achieved with a small rise The flow efficiently buoys the mixture). the

At this time, if the opening of the upflow generation pipe is provided at a designated position in the inclined direction, such as the discharge end side, under the inclined screen, the upflow can only be generated in a part of the water tank, thereby enabling The medium-light specific gravity floats under the water surface, which can reduce the amount of upwelling water. In this case, the upflow generating pipe may be opened at another position below the inclined screen. the

By providing a mechanism for vibrating the inclined screen, the light-to-medium weight objects sunk on the screen can be reliably floated by upflow and selectively attracted to the suction pipe, thereby further improving the screening accuracy. In addition, clogging of the mesh of the screen can also be prevented. the

By providing a storage portion for the mixture thrown into the upper end side of the inclined screen, before reaching the storage portion, the heavy specific gravity is distributed to the lower side and the medium light specific gravity is distributed to the upper side due to the difference in self-weight. Afterwards, the mixture moves to the upper end side of the inclined screen, so the medium-light specific gravity distributed on the upper side can be smoothly floated by the upflow, and can be easily sucked by the suction pipe. the

At this time, if the storage part is connected to the inclined screen, the storage part will also vibrate with the vibration of the inclined screen, so that the mixture reaching the storage part can be promoted to distribute the heavy specific gravity to the On the lower side, the medium and light specific gravity is distributed to the upper side. the

The present invention is as above, because the heavy specific gravity is not attracted but sinks to the bottom of the water tank, so the recovery rate of the heavy specific gravity improves. the

Description of drawings

FIG. 1 is a process diagram showing a process in which a mixture charged into a screening device according to a first embodiment is classified from construction waste. the

Fig. 2 is a longitudinal sectional view showing the screening device according to the first embodiment. the

Fig. 3 is a cross-sectional view along line III-III of Fig. 2 . the

Fig. 4 is a longitudinal sectional view showing a second embodiment. the

Fig. 5 is a longitudinal sectional view showing a third embodiment. the

Fig. 6 is a longitudinal sectional view showing a fourth embodiment. the

Fig. 7 is a longitudinal sectional view showing a fifth embodiment. the

Fig. 8 is a longitudinal sectional view showing a sixth embodiment. the

FIG. 9 is a top view of FIG. 8 . the

10 is a partially omitted longitudinal sectional view showing a first modification example of the sixth embodiment. the

Fig. 11 is a partially omitted longitudinal sectional view showing a second modified example of the sixth embodiment. the

Fig. 12 is a longitudinal sectional view showing a seventh embodiment. the

Fig. 13 is a longitudinal sectional view showing an eighth embodiment. the

Fig. 14 is a partial perspective view of an example of a suction tube. the

In the figure: A, A', A" heavy specific gravity; B medium light specific gravity; C light specific gravity; D mixture; 1 wet screening device; 2 water tank; 2a supply end; 2b discharge end; 3 basket (basket); 3a supply end; 3b discharge end; 4 partition plate; 5 feeding trough (shoot); ₆ inclined screen; ₇ vibration generating mechanism; 9, ₉₁ , ₉₂ suction pipe; 9a opening of suction pipe; 10 conveyor belt (conveyor); 11, 11a discharge screw (screw); 11b discharge port; pump; 13 filter (filter); 14 storage part; 15 discharge 15a opening; 15b outlet; 16 embankment; 17 flexible cover; 18 nozzle; 21 pulverizer; 22 sieve; 23 magnetic separator; 24 pulverizer; 25 sieve.

Detailed ways

Hereinafter, embodiments of the present invention will be described based on the drawings. 1 to 3 show a first embodiment. This screening device 1 is used in a recycling plant for aggregates contained in concrete of construction waste, for removing wood chips and plastic chips mixed in the aggregates. the

As shown in Fig. 1, the concrete is pulverized with a pulverizer 21, and the large foreign matter is removed by hand screening, and then put into a sieve 22 to remove tiny foreign matter with a size of about 2 mm or less, while the large pulverized matter exceeding 40 mm is put back into the pulverizer 21 Re-crushed. The pulverized material whose size is considered to be 40mm or less is removed by the magnetic separator 23, and then ground by the grinder 24 to remove the cement mortar (cement mortar) attached to the aggregate, and sieved by the sieve 25 into five sizes . the

In this embodiment, it is screened into sizes smaller than 7 mm, 7 to 13 mm, 13 to 20 mm, 20 to 28 mm, and 28 to 40 mm, and is charged into the wet screening device 1 . The treated material charged into the wet screening device 1 is a mixture D in which wood chips and plastic chips are mixed in the aggregate. the

As shown in Fig. 2 and Fig. 3, the described wet screening device 1 is as follows: in the vertically wide rectangular tank 2, a horizontally wide rectangular basket 3 with a vertical top opening can be hoisted up and down, and the basket 3 is vertically The dividing plate 4 is cut into 5 rows along its width direction (the left-right direction of FIG. 3 ), and the mixture D that is screened into 5 types of sizes by the sieve 25 is dropped into each row from the feeding trough 5 . the

In addition, the partition position of each partition plate 4 is variable, and the width of each column can be adjusted according to the throughput of each size of the mixture D. the

In addition, an inclined screen 6 is provided on the bottom of the basket 3, which is inclined downward from the supply end 3a where the mixture D is thrown into the discharge end 3b on the other end side, and the inclined screen 6 is passed through the vibration generating mechanism 7 of the basket 3. 6Apply vibration. The vibration generating mechanism 7 changes the overlapping position with the basket 3 by circularly moving the vibration transmission plate 7a (see the arrow in FIG. 2 ), thereby vibrating the basket 3 up and down. the

On each column of the baskets 3 partitioned by the partition plate 4, an upwardly opening upward flow generation pipe 8 is provided to generate an upward flow from above during the inclination of the inclined screen 6, and the suction is floated by the upward flow. The suction pipe 9 of the downward opening of the floating matter in the water. The upflow generation pipe 8 and the suction pipe 9 face each other in an oblique direction, and the distance between the openings 8a, 9a of both is set to a distance at which the upflow does not weaken. In addition, the lower end side of the inclined screen cloth 6 at the discharge end 3b of the basket 3 is opened, and a conveyor belt 10 for fishing floating objects on the water surface is provided near the water surface outside it, and at the bottom of the water tank 2 at the discharge end 3b side, a There is a discharge screw 11 for discharging sediment. the

Put the mixture D into each row of the basket 3 from the feeding chute 5, the heavy specific gravity such as aggregates A quickly sinks on the inclined screen 6, and after the inclined screen 6 is moved downward toward the discharge end 3b side , sinks from the open discharge end 3b on the lower end side to the bottom of the water tank 2, and is screened and recovered by the rotating discharge screw 11. Part of the heavy specific gravity material A floats in the water due to the upflow from the upflow generation pipe 8 during the downward movement on the inclined screen 6, but sinks without riding on the upflow toward the obliquely upward direction of the suction pipe 9. onto the inclined screen 6. the

In addition, even if the heavy object A rides the water flow and is sucked by the suction pipe 9, since the suction pipe 9 opens downward and slopes upward from the opening 9a, the sinking force due to its own weight exceeds the buoyancy force (attractive force) caused by the suction. ), it will still sink to the inclined screen cloth 6 below again. the

Also, the upward inclination angle of the suction pipe 9 can be adjusted, and the boundary of the specific gravity of whether the suction pipe 9 can be sucked can be adjusted. The more gentle the upward inclination angle of the suction pipe 9 is, the more the suction pipe 9 can attract objects with large specific gravity. the

In addition, the flow velocity of the upward flow and the flow velocity in the suction pipe 9 are set to be larger as the size of the mixture is larger. the

In addition, the upflow from the upflow generating pipe 8 and the suction flow from the suction pipe 9 are formed by one pump (see FIG. 5 ), or are formed by separate pumps. At this time, the suction force (suction flow rate) of the suction pipe 9 is appropriately set so that the flow cross-sectional area of the suction pipe 9 and the capacity of the pump can sink by its own weight even if the heavy object A enters the suction pipe 9 etc., and suitably set the flow cross-sectional area of the upflow generating pipe 8 and the like in conjunction with it. the

Among the wood chips and plastic chips included in the input mixture D, the medium-light specific gravity objects B with a specific gravity larger than 1 slowly deposit and move down to the inclined screen 6. It floats in the water by ascending current, is sucked by the suction pipe 9, and is discharged to the outside. In addition, the light specific gravity object C having a specific gravity smaller than 1 floats on the water surface, moves toward the discharge end 3b side, is scooped up by the conveyor belt 10, and is discharged to the outside. the

Also, because the inclined screen 6 is vibrated, even if the medium-light specific gravity object B is on the lower side of the heavy specific gravity object A with a larger specific gravity, it can naturally become the upper side through vibration, and it can be ensured by the upflow. floating. In addition, the inclined screen 6 will not block the mesh. the

Fig. 4 shows a second embodiment. This screening device 1 also screens aggregates from the mixture D mainly composed of aggregates. Like the first embodiment, an inclined screen 6 is installed at the bottom of a horizontally wide basket 3 hoisted in a horizontally wide water tank 2. , in the inclined way of the inclined screen 6, an upflow generation pipe 8 for generating an upflow from below, and a suction pipe 9 for attracting floating objects floating under the water surface due to the upflow are provided.

The basket 3 is not separated by a partition plate, and the mixture injected into the supply end 3a from the feeding trough 5 is not divided into different sizes. After the heavy specific gravity A sinks on the inclined screen 6 and moves downward, it sinks from the discharge end 3b on the lower end side. Down to the bottom of the water tank 2, screened and recovered by the discharge screw 11. In addition, the medium-light specific gravity object B sinks on the inclined screen 6 and moves downward. During this process, the upflow from the upflow generation pipe 8 is used to float under the water surface, and it is sucked by the suction pipe 9 and discharged to the outside. The light specific gravity The object C floats on the water surface, moves to the side of the discharge end 3b, is picked up by the conveyor belt 10, and is discharged to the outside. the

In addition, even if the heavy object A rides the water flow and is sucked by the suction pipe 9, the sinking force brought by its own weight exceeds the buoyancy (attractive force) caused by the suction, and it will sink to the inclined screen 6 below again. the

Also in this embodiment, the vibration generating mechanism 7 can be suitably employed. the

Fig. 5 shows a second embodiment. This screening device 1 does not have the above-mentioned basket 3, and a plurality of upflow generation pipes 8 are arranged in such a manner that the bottom is substantially completely covered along the bottom of the horizontally wide water tank 2 from the side of the supply end 2a to the side of the discharge end 2b. . Under the water surface, as in the second embodiment, the suction pipe 9 opens downward, and the water in the water tank 2 is sucked to the suction pipe 9 by the pump 12, and the sucked water passes through the filter 13 to remove the medium and light specific gravity objects B and then is recycled for use again. , so that it is sprayed from each upflow generating pipe 8 so as to generate an upflow in the water tank 2 . In addition, near the water surface on the side of the discharge end 2b, a conveyor belt 10 for fishing floating objects on the water surface is provided, and a discharge screw 11 is provided at the bottom on the side of the discharge end 2b. the

In this embodiment, the mixture D thrown into the supply end 2a of the water tank 2 from the feeding tank 5, the heavy specific gravity material A that sinks descends and moves to the bottom of the water tank 2 inclined downward to the side of the discharge end 2b, and is discharged by the discharge screw. 11 Screening and recovery, the slowly sinking medium-light specific gravity objects B are floated in the water by the upflow from each upflow generation pipe 8, and are sucked by the suction pipe 9 and discharged to the outside. In addition, the light specific gravity objects C floating on the water surface are scooped up by the conveyor belt 10 and discharged to the outside. In addition, even if the heavy object A rides the water flow and is attracted by the suction pipe 9, the sinking force brought by its own weight exceeds the buoyancy (attractive force) caused by the attraction, it will still sink to the bottom surface of the water tank 2 again. Inclined movement to discharge screw 11. the

FIG. 6 shows a fourth embodiment. The screening device 1 is provided with a plurality of suction pipes 9 in sequence along the flow direction of the mixture D in a plan view of the water tank 2, and each of the suction pipes 9 ₁ , 9 ₂ ... is provided with upflow generation pipes 8 ₁ , 8 ₂ ... , the suction force of the respective suction pipes 9 ₁ , 9 ₂ ... and the upward force of the upward flow generating pipe 8 are sequentially strengthened toward the flow direction.

In this embodiment, since the suction pipes _{9 1} , 9 _{2 .} Changes in flow velocity and ascending (discharging) flow velocity can change suction and ascending force.

In this embodiment, the medium light specific gravity object B floating in the water by the upward flow from the upward flow generating pipe ₈₁ is sucked and discharged by the suction pipe ₉₁ , while the heavy specific gravity object A' having a relatively small specific gravity such as aggregate passes through. The strong upflow from the second upwelling generating pipe ₈₂ floats in the water, and is sucked out by the second suction pipe ₉₂ with strong suction force. In addition, the heavy specific gravity A' slightly heavier than the heavy specific gravity A' passes through. The strong upwelling from the 3rd upflow generation pipe ₈₃ floats in the water, and is sucked out by the 3rd suction pipe ₉₃ of strong suction. At this time, even if the heavy specific gravity objects A, A', A" are attracted by the water flow Tubes 9 ₁ , 9 ₂ ... are attracted, and they will also be directly attracted by the suction tubes 9 ₁ , 9 ₂ .... The sinking force brought by their own weight exceeds the buoyancy (attractive force) caused by the suction, and they will still It sinks down on the inclined screen 6 below again, and then sinks down into the lower end side discharge end 2 b of the water tank 2 .

In this way, a three-stage attraction screening is carried out, and the heavy specific gravity object A is screened to distinguish the specific gravity (A', A"), and only metals such as steel, copper, lead, etc. have a very large specific gravity and sink as the heavy specific gravity object A. Down into the discharge screw 11, it is screened out from the discharge end 2b on the lower end side of the water tank 2.

In this embodiment, the basket 3, the inclined screen 6, the vibration generating mechanism 7, and the like can be appropriately employed. In addition, the numbers of the suction pipes 9 and the upflow generating pipes 8 are appropriately set according to the number of mixtures D to be screened. In addition, as shown in the dotted line in the figure, if the inclined screen 6 is provided, as shown in FIG. 4, since the mixture D moves thereon, the screening effect will be surely exerted. the

Fig. 7 shows a fifth embodiment. This screening device 1 is as follows, the water tank 2 is long and deep, and the mixture D is thrown in from the feed tank 5 inserted into the water of approximately the middle depth. A plurality of upward flow generating pipes 8 are provided below the feed tank 5 to cover almost the entire cross section of the water tank 2, and a suction pipe 9 opening downward is provided above the feed tank 5. Like the third embodiment, The pump 12 sucks the water in the water tank 2 to the suction pipe 9, and the sucked water passes through the filter 13 to remove the medium and light specific gravity objects B and then is recycled, and again, it is drawn from the water tank 2 in such a way that an upward flow occurs. Each upflow generating pipe 8 discharges. In addition, a conveyor belt 10 for fishing floating objects on the water surface is provided near the water surface, and a discharge screw 11 is provided at the bottom. the

In this embodiment, among the mixture D that is put into the water from the feed tank 5, the heavy specific gravity objects A that sink to the bottom of the water tank 2 are screened and recovered by the discharge screw 11, and the medium and light specific gravity objects B can pass through the upflow generating tubes. The upwelling of 8 floats in the water, is sucked by suction pipe 9 and discharged to the outside. The light specific gravity objects C floating on the water surface are picked up by the conveyor belt 10 and discharged to the outside. In addition, even if the heavy object A rides the water flow and is attracted by the suction pipe 9, the sinking force due to its own weight exceeds the buoyancy (attractive force) due to the suction, and it will sink down again. the

8 and 9 show a sixth embodiment. The screening device 1 is as follows. Like the first embodiment, the horizontally wide baskets 3 hoisted in the horizontally wide water tank 2 are divided into five rows by the partition plate 4, and the mixture D is screened into five types of sizes from the feeding tank 5. into each column. the

On the side of the supply end 3a of the basket 3 into which the mixture D is dropped, a bottomed storage portion 14 is provided, and on the bottom of the storage portion 14, like the first embodiment, a bottom slanted downward to the side of the discharge end 3b is connected. The inclined screen 6 (continuous) vibrates the bottom of the storage part 14 and the inclined screen 6 via the vibration mechanism 7 attached to the basket 3 . the

The bottom of the storage portion 14 is slightly inclined toward the inclined screen 6 side, and the inclined end side is provided with a discharge screw 15, which penetrates the side walls of the water tank 2 and the basket 3 and the partition plates 4 of each row on the water surface. , the light specific gravity materials C floating on the water surface of each row are discharged to the outside from the openings 15a opened in each row. On the rear side of the discharge screw 15, a dam 16 is provided to intercept the light specific gravity material C floating on the water surface. the

Also, the vibration generating mechanism 7 is installed on the side wall of the basket 3 above the discharge screw 15, and the side wall part of the water tank 2 through which the discharge screw 15 penetrates is transmitted through the side wall of the basket 3 and the discharge screw 15 in order to absorb vibration. vibration, while the surrounding side walls are connected by a flexible covering layer 17. the

In addition, during the inclination of the inclined screen 6, each row of the baskets 3 is provided with an upflow generating pipe 8 for generating an upflow from below, and a suction pipe 8 for attracting floating objects floating in the water by the upflow. The pipes 9 are arranged so that the respective openings 8a, 9a are formed in substantially the entire width direction of the inclined screen 6, facing each other up and down. Each upflow generating pipe 8 and each suction pipe 9 are divided and arranged into each row, and the respective openings 8a, 9a of each row are in the shape of long holes with a rectangular cross-section, and the cross-sectional area of the opening 9a of each suction pipe 9 and its inlet portion, It is formed to be larger than the area of the opening 8 a of each upflow generating pipe 8 . the

In addition, at the bottom of the water tank 2 on the side of the discharge end 3b, a discharge screw 11 for discharging the sediment is provided as in the first embodiment. the

In this embodiment, the mixtures D of different sizes are put into the storage parts 14 of each row from the feeding chute 5, and the heavy specific gravity objects A are distributed to the lower side by the vibration applied to the bottom of the storage parts 14, and the medium and light specific gravity Object B is distributed to the upper side.

Then, keeping this state, the lower side of the embankment 16 moves to the upper end side of the inclined screen cloth 6, and the medium-light specific gravity objects B still distributed on the upper side on the inclined screen cloth 6 pass through the rise from each upflow generating pipe 8. The flow floats in the water, is sucked by each suction pipe 9, and is discharged to the outside. the

The heavy specific gravity material A moving while being distributed on the lower side on the inclined screen 6, even if it enters the suction pipe 9 due to the upflow, will sink to the inclined screen 6 again, and from the lower end of the inclined screen 6 The side discharge end 3b sinks into the discharge screw 11 at the bottom of the water tank 2, and is screened and recovered from the discharge port 11b. The flow velocity of the ascending flow and the flow velocity in the suction pipe 9 are, for example, set to 0.7 m per second in the smallest size row, and set to 1.8 m per second in the largest size row. the

In this way, since the suction speed is set according to the size of the mixture D, even if heavy objects A are sucked by the suction pipes 9, they will exceed the specified specific gravity and sink to the inclined screen 6 below again. the

In addition, the light specific gravity substances C in the mixture of each row having different sizes float to the surface of the water, enter each opening 15a of the rotating discharge screw 15, and are discharged outside together from the discharge port 15b thereof. the

FIG. 10 shows a first modified example of the sixth embodiment. In this first modified example, the upward flow generation pipe 8 and the suction pipe 9 provided on the inclined middle of the inclined screen 6 are closer to the discharge end 3b side of the basket 3, so that the upper and lower sides of the inclined screen 6 The side openings 8a, 9a are provided facing each other with a second upflow generating pipe 8 ₂ capable of generating a stronger upflow than the upflow generating pipe 8 , and a second suction pipe 9 ₂ having a stronger suction force than the suction pipe 9 .

In this first modified example, the medium light specific gravity object B floating in the water by the upflow from the upward flow generating pipe ₈₁ is sucked and discharged by the suction pipe ₉₁ , while the heavy specific gravity object A' with a relatively small specific gravity such as aggregate The strong upwelling from the second upwelling generating pipe ₈₂ floats in the water, and is suctioned and discharged by the second suction pipe ₉₂ with strong suction. At this time, if the heavy specific gravity objects A and A' are attracted by the suction pipes 9 ₁ and 9 ₂ by the water flow, the sinking force brought by the two specific gravity objects A and A' together in the front suction pipe 9 ₁ will Exceed the buoyancy (attractive force) that attracts to cause, sink again on the inclined screen cloth ₆ of below, the gravity object A such as iron, copper, lead etc. The resulting buoyancy sinks to the inclined screen 6 below again, and the heavy objects A' with relatively small specific gravity such as aggregates are directly attracted and exported to the outside.

Therefore, a two-stage attraction screening was performed, and heavy specific gravity A was screened to distinguish specific gravity (A and A'), and only metals such as steel, copper, and lead had a very large specific gravity and sank as heavy specific gravity A Into the discharge screw 11, it is screened out from the lower end side discharge end 3b of the inclined screen 6. the

FIG. 11 shows a second modified example of the sixth embodiment. In this second modified example, a second discharge screw 11a is provided on the front side of the discharge screw 11 provided at the bottom of the discharge end side of the water tank 2, and a nozzle that generates a forward horizontal flow from the discharge end side of the water tank 2 is provided. 18. the

Therefore, among the heavy objects A sinking from the discharge end 3b on the lower end side of the inclined screen 6, the heavy objects A' having a relatively small specific gravity such as aggregates sink under the influence of the horizontal flow from the nozzle 18. Going down to the second discharge screw 11a ahead, only the heavy specific gravity objects A with very high specific gravity of metals such as steel, copper, lead, etc. sink directly into the discharge screw 11 and are screened out. the

In the modified example of FIG. 10, FIG. 11, the number of the upflow generation pipe 8 and the suction pipe 9 is arbitrary. the

In Fig. 12 and Fig. 13 , the seventh and eighth embodiments are shown, and these two embodiments are the first and second modified examples of the fifth embodiment shown in Fig. 7 , and the embodiment in Fig. 12 uses the suction tube 9 is arranged in two numbers 9 ₁ and 9 ₂ , and in the embodiment shown in Fig. 13 , the upflow generating tube 8 is arranged in two numbers 8 ₁ and 8 ₂ . The suction force of the two suction pipes 9 ₁ and 9 ₂ makes the suction pipe 9 ₁ on the upstream side weaker than the suction pipe 9 ₂ on the downstream side, and the ejection force of the two upflow generating pipes 8 ₁ and 8 ₂ also makes the upflow on the upstream side occur The pipe ₈₁ is weaker than the downstream side generating pipe ₈₂ , and thus, it is possible to sort heavy specific gravity objects A and A' similarly to the embodiment of FIG. 10 . At this time, even if the specific gravity objects A, A' are attracted by the suction pipes 9 ₁ , 9 ₂ by the water flow, they will be directly attracted according to the suction force of the suction pipes 9 ₁ , 9 ₂ , and the sinking force brought by their own weight Exceeding the buoyancy (attractive force) caused by attraction, it will still sink to the bottom again.

Including the above-described embodiments, the shape of the inlet portion of the suction pipe 9 may be as shown in FIG. 14 , and the shape of the inlet of the upflow generating pipe 8 may be the same. In this embodiment, the number of upflow generating tubes 8 and suction tubes 9 is arbitrary. the

In each of the above-described embodiments, the heavy objects A may be sunk from the meshes of the inclined screen 6 , and members that are not included in the respective embodiments can be appropriately employed in the embodiments that do not have the members. For example, the storage portion 14 can be suitably employed in each of the embodiments shown in FIGS. 2 , 4 , and 6 . the

Each of the embodiments is for the screening of concrete aggregates of construction waste, but these embodiments can also be applied to the separation and removal of gravel and the like from the above-mentioned papermaking sawdust and the screening of shotguns at a skeet shooting range. , the effect of improving the screening accuracy can be obtained. In these cases, the number of upflow generating pipes 8 and suction pipes 9, the presence or absence of inclined screens 6, and the like can be appropriately set according to the object to be screened. For example, in the case of a shotgun, since there is one object to be screened, only one upflow generating tube 8 and one suction tube 9 is sufficient.

Claims (24)

1. A screening device (1), which drops the screened mixture (D) into the water tank (2), uses its specific gravity difference to screen the heavy specific gravity (A) in the mixture (D) that sinks to the bottom of the water tank ), characterized in that, In the water tank (2), there are provided an upflow generation pipe (8) for generating an upflow, and a suction pipe (8) for attracting floating objects floating in the water due to the upflow from the downward opening (9a). Pipe (9), set the suction force of this suction pipe (9), so that even if the heavy specific gravity (A) enters in the suction pipe (9), it will sink by its own weight. 2. The screening device according to claim 1, characterized in that, the suction flow velocity of the suction pipe (9) is slower than the flow velocity of the upward flow, so that even if the heavy specific gravity (A) enters the suction pipe ( 9) will also sink by its own weight. 3. The screening device according to claim 2, characterized in that, the opening area of the upflow generation pipe (8) is larger than the area of the opening (9a) of the suction pipe (9) that is sucked upward. The flow cross-sectional area of the inlet portion of the suction pipe (9) is narrow, so that the suction flow velocity of the suction pipe (9) is slower than the flow velocity of the upward flow. 4. The screening device according to any one of claims 1 to 3, characterized in that, the water tank (2) is divided into multiple rows with a vertical dividing plate (4), and in each of these separated The suction tubes (9) are respectively arranged in columns. 5. The screening device according to claim 4, characterized in that, the mixture (D) that is dropped into the water tank (2) is classified in size, and these mixtures (D) that have been classified in size are dropped into the said water tank (2) respectively. in separate columns. 6. The screening device according to any one of claims 1 to 3, characterized in that, a plurality of suction pipes (9) are sequentially arranged towards the flow direction of the mixture (D), and a plurality of suction pipes (9) are sequentially arranged towards the flow direction. The suction force of each suction tube (9 ₁ , 9 ₂ ) is strengthened. 7. screening device according to claim 4, is characterized in that, toward the flow direction of described mixture (D), a plurality of described suction pipes (9) are arranged successively, strengthen each suction pipe (9) toward described flow direction successively ( 9 ₁ , 9 ₂ ) of attraction. 8. screening device according to claim 5, is characterized in that, toward the flow direction of described mixture (D), a plurality of described suction pipes (9) are arranged successively, strengthen this each suction pipe (9) toward described flow direction successively ( 9 ₁ , 9 ₂ ) of attraction. 9. The screening device according to claim 4, characterized in that an upflow generating tube (8) is respectively provided for each of the suction tubes (9). 10. The screening device according to claim 5, characterized in that an upflow generating tube (8) is respectively provided with respect to each of the suction tubes (9). 11. The screening device according to claim 6, characterized in that an upflow generating tube (8) is respectively provided with respect to each of the suction tubes (9). 12. The screening device according to any one of claims 9-11, characterized in that the upflow of each upflow generating tube (8) is intensified sequentially toward the flow direction of the mixture (D). 13. The screening device according to any one of claims 1 to 3, 5 and 7 to 11, characterized in that the openings (8a, 9a) of the upflow generating tube (8) and the suction tube (9) are ) each form a long hole shape that is long in the transverse direction with respect to the flow direction of the mixture (D). 14. The screening device according to claim 4, characterized in that, the openings (8a, 9a) of the upflow generating pipe (8) and the suction pipe (9) are respectively formed to be opposite to the mixture (D). The shape of a long hole in which the flow direction is long in the horizontal direction. 15. The screening device according to claim 6, characterized in that, the openings (8a, 9a) of the upflow generating pipe (8) and the suction pipe (9) are respectively formed to be opposite to the mixture (D). The shape of a long hole in which the flow direction is long in the horizontal direction. 16. The screening device according to any one of claims 1-3, 5, 7-11, 14-15, characterized in that the upflow generating pipe (8) in the water tank (2) Between the suction pipe (9) and towards the flow direction of the mixture (D), an inclined screen (6) with the lower end as the discharge end is set downwards, and the upper end of the inclined screen (6) is put into The mixture (D) sinks the specific gravity (A) to the bottom of the water tank from the discharge end on the lower end side. 17. The screening device according to claim 4, characterized in that, between the upflow generating pipe (8) and the suction pipe (9) in the water tank (2), towards the mixture (D) In the flow direction, the inclined screen (6) whose lower end is opened as the discharge end is inclined downward, and the mixture (D) is put into the upper end side of the inclined screen (6), and the discharge end of the lower end side is used. The heavy specific gravity (A) sinks to the bottom of the water tank. 18. The screening device according to claim 6, characterized in that, between the upflow generating pipe (8) and the suction pipe (9) in the water tank (2), towards the mixture (D) In the flow direction, the inclined screen (6) whose lower end is opened as the discharge end is inclined downward, and the mixture (D) is put into the upper end side of the inclined screen (6), and the discharge end of the lower end side is used. The heavy specific gravity (A) sinks to the bottom of the water tank. 19. The screening device according to claim 12, characterized in that, between the upflow generating pipe (8) and the suction pipe (9) in the water tank (2), towards the mixture (D) In the flow direction, the inclined screen (6) whose lower end is opened as the discharge end is inclined downward, and the mixture (D) is put into the upper end side of the inclined screen (6), and the discharge end of the lower end side is used. The heavy specific gravity (A) sinks to the bottom of the water tank. 20. The screening device according to claim 13, characterized in that, between the upflow generating pipe (8) and the suction pipe (9) in the water tank (2), toward the mixture (D) In the flow direction, the inclined screen (6) whose lower end is opened as the discharge end is inclined downward, and the mixture (D) is put into the upper end side of the inclined screen (6), and the discharge end of the lower end side is used. The heavy specific gravity (A) sinks to the bottom of the water tank. 21. The screening device according to any one of claims 17-20, characterized in that a mechanism for applying vibration to the inclined screen (6) is provided. 22. Screening device according to claim 16, characterized in that a mechanism for applying vibration to the inclined screen (6) is provided. 23. The screening device according to claim 21, characterized in that, on the upper end side of the inclined screen (6), a storage part (14) for the injected mixture (D) is connected. 24. The screening device according to claim 22, characterized in that, on the upper end side of the inclined screen (6), a storage part (14) for the injected mixture (D) is connected.

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