JP7187210B2 - dust collector - Google Patents

Description

TECHNICAL FIELD The present invention relates to a dust collecting device for collecting powdery dust scattered inside a dust generating section.

Among raw materials handled in batcher plants for producing ready-mixed concrete, solid raw materials such as gravel, sand, cement, etc. contain fine powder (hereinafter sometimes simply referred to as "dust"). Such fine dust tends to be stirred up in the apparatus, and if the dust is left as it is, the dust adheres to the inner walls and moving parts of the apparatus and solidifies, making cleaning difficult. In addition, in the mixing tank of a mixer that mixes solid raw materials with liquid raw materials, etc., a camera may be installed to check the internal state of the mixing tank. Shooting may be hindered. For this reason, the part where such dust is generated (hereinafter sometimes referred to as "dust generating part") is provided with a dust collecting device for collecting the dust scattered inside the dust generating part. (for example, the dust collection device described in Patent Document 1).

The dust collector described in Patent Document 1 includes a suction pipe 16, a dust collector 15, a delivery pipe 19, and an air supply means 21, as shown in FIG. It is for collecting the dust scattered inside the mixer 1. A first on-off valve 18 is provided at the powder discharge port of the dust collector 15 , and a second on-off valve 20 is provided at the intermediate portion of the delivery pipe 19 . In the dust collection device described in the same document, the dust that has risen up in the mixer 1 is sucked through the suction pipe 16 and stored in the hopper 25 of the dust collector 15 for several batches. When a certain amount of dust accumulates, the first on-off valve 18 is opened to move the dust from the hopper 25 to the delivery pipe 19, and when the movement of the dust is completed, the first on-off valve 18 is closed. After that, the second on-off valve 20 is opened, and the air supply means 21 causes the compressed air to flow into the delivery pipe 19 , so that the dust inside the delivery pipe 19 is returned to the mixer 1 .

JP-A-10-113524

However, since the dust collecting device described in Patent Document 1 is provided with the second on-off valve 20 in the intermediate portion of the delivery pipe 19, the flow resistance in the delivery pipe 19 is large, and the air supply means 21 Even if the dust in the delivery pipe 19 is to be sent out by the , there is a problem that part of the dust is caught in the second on-off valve 20 and remains in the delivery pipe 19 . If dust remains in the delivery pipe 19, the inside of the delivery pipe 19 becomes narrow, and the dust cannot be delivered efficiently. There is also a risk that the valve 20 will become difficult to open and close, and that the delivery pipe 19 will be blocked.

In addition, the dust collecting device described in Patent Document 1 also has a problem that the collected dust cannot be efficiently delivered to the mixer 1 when the amount of dust to be collected is large. Specifically, in the dust collecting device described in the document, the amount of dust stored in the hopper 25 is large, and even if the first on-off valve 18 is opened, the entire amount of accumulated dust is transferred to the delivery pipe 19. If it is not possible, [1] once close the first on-off valve 18 while the dust remains in the hopper 25, Send out the dust inside, [3] close the second on-off valve 20 after sending out, and [4] reopen the first on-off valve 18 to move the remaining dust to the delivery pipe 19. It may be necessary to repeat. This is because when the first on-off valve 18 and the second on-off valve 20 are opened at the same time, moist air inside the mixer 1 flows through the delivery pipe 19 into the dust collector 15, which is in a negative pressure state. Since the dust inside the delivery pipe 19 and the dust collector 15 contains moisture and solidifies, one of the first on-off valve 18 and the second on-off valve 20 must always be closed. is. Therefore, when the amount of dust to be collected is large and the speed of accumulation of dust in the hopper 25 exceeds the speed of sending dust to the mixer 1, the inside of the dust collector 15 becomes full of dust with the lapse of time. may be damaged.

SUMMARY OF THE INVENTION An object of the present invention is to provide a dust collecting apparatus capable of smoothly returning collected dust to a dust generating portion. It is another object of the present invention to provide a dust collecting apparatus capable of efficiently returning the dust to the dust generating section even when the amount of dust to be collected is large.

The above issues are
A dust collecting device for collecting powdered dust scattered inside a dust generating part,
a suction pipe for sucking the dust in the dust generating portion together with the air;
a first storage tank for storing dust sucked by the suction pipe;
A first valve that opens and closes the first dust delivery port provided at the bottom of the first storage tank;
a second storage tank disposed below the first storage tank and having an upper portion connected to the first storage tank via a first valve;
a second valve for opening and closing the second dust delivery port provided at the bottom of the second storage tank;
The upstream side is connected to the second storage tank via the second valve, and the downstream end is connected to the dust generating part, and the dust sent out from the second storage tank is returned to the inside of the dust generating part. a tube;
To provide a dust recovery device comprising a compressed air jetting means for sending the dust sent into the return pipe from the second storage tank to the dust generating part by jetting the compressed air from upstream to downstream of the return pipe. resolved by

The dust recovery apparatus of the present invention does not require a valve in the flow path (return pipe) for returning the collected dust to the dust generating portion by the compressed air ejection means, and can reduce the flow resistance in the return pipe. It is a thing. Therefore, the dust collecting device of the present invention can smoothly return the dust to the dust generating portion. In addition, in the dust recovery apparatus of the present invention, as will be described in detail later, the provision of the second storage tank allows the dust to be efficiently transferred to the dust generating section even when the amount of dust to be recovered is large. It can be sent back.

In the dust recovery device of the present invention, it is preferable to provide a throttle portion at the connecting portion between the second valve and the return pipe. This makes it difficult for the compressed air ejected into the return pipe from the compressed air ejection means to flow into the second storage tank, so that the dust can be more efficiently returned to the dust generating section.

In the dust recovery device of the present invention, the dust falls from the ejection port of the ejection nozzle for ejecting the compressed air into the return pipe in the compressed air ejection means when the dust is sent out from the second storage tank in the return pipe. It is preferable to arrange it near the location. As a result, the compressed air ejected from the compressed air ejecting means can be applied to the dust more accurately, and the dust in the return pipe can be more efficiently returned to the dust generating portion.

It is preferable that the dust collecting apparatus of the present invention further comprises second storage tank dust adhesion suppression means for suppressing dust from adhering to the inner wall of the second storage tank. As a result, the dust recovery rate can be increased, and the dust adhering to the inner wall of the second storage tank can be prevented from solidifying and fixing.

INDUSTRIAL APPLICABILITY As described above, the present invention provides a dust collecting device capable of smoothly returning the collected dust to the dust generating section. Further, it is possible to provide a dust collecting device capable of efficiently returning the dust to the dust generating section even when the amount of dust to be collected is large.

It is a figure showing the whole dust collection device of the present invention. FIG. 4 is a partial cross-sectional view of the dust recovery device of the present invention, showing a state in which dust is stored in the first storage tank. FIG. 4 is a partial cross-sectional view of the dust recovery device of the present invention, showing a state in which the first valve is opened and dust is sent from the first storage tank to the second storage tank. FIG. 4 is a partial cross-sectional view of the dust recovery device of the present invention, showing a state in which the second valve is opened and the dust is sent from the second storage tank to the return pipe. FIG. 4 is a partial cross-sectional view of the dust recovery device of the present invention, showing a state in which the dust in the return pipe is returned to the mixing tank by the compressed air jetted from the compressed air jetting means. FIG. 4 is a partial cross-sectional view of the dust recovery apparatus of the present invention, showing a state in which the dust remaining in the second storage tank is sent into the return pipe after the dust in the return pipe is returned to the mixing tank. It is a diagram.

A preferred embodiment of the present invention will be described more specifically with reference to the drawings. FIG. 1 is a diagram showing the entire dust collection device 100 of the present invention. In the following, a case will be described in which the dust recovery apparatus 100 of the present invention is used to recover scattered dust in the mixing tank 210 (dust generation section) of the mixer 200 that mixes the solid raw material and the liquid raw material. However, as will be explained in detail later, the dust collection device 100 of the present invention can be used in any device in which dust can be dispersed. As shown in FIG. 1, the dust collecting device 100 includes a suction pipe 110, a first storage tank 120, a second storage tank 130, a return pipe 140, and a compressed air jet means 150. there is

The suction pipe 110 is for sucking the dust inside the mixing tank 210 together with the air, and is connected to the mixing tank 210 of the mixer 200 at its upstream side and to the first storage tank 120 at its downstream side.

The first storage tank 120 is for storing dust sucked by the suction pipe 110 . The lower part of the first storage tank 120 is a funnel-shaped hopper, and the bottom of this hopper is provided with a first dust delivery port 121 for delivering the stored dust. The first dust delivery port 121 is provided with a first valve 122 that is opened and closed by a first drive means 122a.

The second storage tank 130 is provided below the first storage tank 120 and serves to store the dust delivered from the first storage tank 120 . The upper part of the second reservoir 130 is connected to the first reservoir 120 via the first valve 122 . A second dust delivery port 131 for delivering dust is provided at the bottom of the second storage tank 130 . The second dust delivery port 131 is provided with a second valve 132 that is opened and closed by a second drive means 132a.

The return pipe 140 is provided below the second storage tank 130 and serves to return the dust sent from the second storage tank 130 to the mixing tank 210 of the mixer 200 . The upstream side of the return pipe 140 is connected to the second storage tank 130 via the second valve 132, and a throttle portion 141 is provided at the connecting portion. The downstream end of the return pipe 140 is connected to the mixing tank 210 .

The compressed air ejection means 150 is connected to the upstream end of the return pipe 140, and ejects the compressed air from the upstream to the downstream of the return pipe 140, thereby discharging the air from the second storage tank 130 into the return pipe 140. The dust sent to the mixing tank 210 is returned to the mixing tank 210 .

2 to 6 are partial cross-sectional views of the dust recovery device 100 of the present invention, in which the dust D stored in the first storage tank 120 is mixed with the mixing tank of the mixer 200 (not shown in FIGS. 2 to 6). However, it is connected to the downstream end of the return pipe 140. The same applies hereinafter.). 2 to 6, the suction pipe 110 (see FIG. 1), the upper portion of the first storage tank 120, and the downstream portion of the return pipe 140 in the dust collecting device 100 are omitted. The operation cycle of the dust collection device 100 will be described in detail below with reference to FIGS.

The operation cycle of the dust recovery device 100 is divided into four stages: a dust suction stage, a first dust delivery stage, a second dust delivery stage, and a dust return stage.

First, the dust suction stage will be described. When the solid raw material containing dust is introduced into the mixing tank 210 from the inlet 220 (see FIG. 1) of the mixer 200, the dust rises inside the mixing tank 210. As shown in FIG. The dust collecting device 100 in the dust suction stage sucks the dust together with the air through the suction pipe 110 . A suction force generating device (not shown) that generates a suction force for suctioning dust by the suction pipe 110 is not particularly limited in its installation location, and can be provided inside the suction pipe 110, but in this embodiment is provided in the upper part inside the first storage tank 120 . The sucked dust D is separated from the air and stored in the first storage tank 120 as shown in FIG. At this time, the first valve 122 is closed. When a predetermined time has passed since the start of the dust suction stage, the dust suction stage ends, and the next first dust delivery stage is started. The transition from the dust suction stage to the first dust delivery stage may be performed based on the amount of dust D accumulated in the first storage tank 120 .

Next, the first dust delivery stage will be described. In the first dust delivery stage, as shown in FIG. 3, the first valve 122 of the first dust delivery port 121 is opened. Then, the dust D stored in the first storage tank 120 is sent out to the second storage tank 130 arranged below the first storage tank 120 by gravity. At this time, the second valve 132 is closed, so the dust D sent from the first storage tank 120 is accumulated in the second storage tank 130 . The second storage tank 130 has a capacity capable of storing the entire amount of dust D stored in the first storage tank 120 during the dust suction stage, and the first storage tank 120 is kept almost empty. can be done.

In this first dust delivery step, if the dust D adheres to the inner wall of the first storage tank 120 and remains there, there is a risk that the recovery rate of the dust D will decrease, or that the adhered dust D will solidify and settle. be. Therefore, the first storage tank 120 may be provided with a first storage tank dust adhesion suppressing means for suppressing the dust D from adhering to the inner wall of the first storage tank 120 . In the dust collection device 100 of this embodiment, the first vibration generator 120a is provided as the first storage tank dust adhesion suppressing means. The first vibration generator 120 a suppresses the dust D from adhering to the inner wall of the first storage tank 120 by vibrating the wall surface of the first storage tank 120 . When the dust D stored in the first storage tank 120 is delivered to the second storage tank 130, the first valve 122 is closed again, the first dust delivery stage is completed, and the next second dust delivery stage is started. do.

Next, the second dust delivery stage will be described. In the second dust delivery stage, as shown in FIG. 4, the second valve 132 of the second dust delivery port 131 is opened. Then, due to gravity, the dust D stored in the second storage tank 130 is sent to the dust receiving portion 140a of the return pipe 140 (the portion of the return pipe 140 where the dust D falls from the second storage tank 130). be done. Here, since the dust D is in the form of fine powder, there is a possibility that a sufficient amount of the dust D will not be delivered to the dust receiving portion 140a if left to gravity alone. However, in the dust recovery device 100 of the present invention, the portion downstream of the second valve 132 is in a negative pressure state, and this negative pressure facilitates the smooth delivery of the dust D to the dust receiving portion 140a. there is This is because the portion downstream of the second valve 132 in the dust recovery device 100 communicates with the inside of the mixing tank 210 (see FIG. 1) of the mixer, and the inside of the mixing tank 210 is in the dust suction stage. This is because the internal air is sucked to create a negative pressure state.

In this second dust delivery step, if the dust D adheres to the inner wall of the second storage tank 130 and remains there, there is a risk that the recovery rate of the dust D will decrease, or that the adhering dust D will solidify and settle. be. For this reason, the second storage tank 130 may be provided with second storage tank dust adhesion suppression means for suppressing the dust D from adhering to the inner wall of the second storage tank 130 . In the dust collection device 100 of this embodiment, a second vibration generator 130a and a compressed air inflow device 130b are provided as second storage tank dust adhesion suppressing means. The first vibration generator 120 a suppresses the dust D from adhering to the inner wall of the second storage tank 130 by vibrating the wall surface of the second storage tank 130 . On the other hand, the compressed air inflow means 130b causes the compressed air to flow into the second storage tank 130 to generate an air current in the second storage tank 130, thereby brushing off the dust D adhering to the inner wall of the second storage tank 130. It is a thing. In the second dust delivery stage, when the compressed air inflow means 130b is operated to flow compressed air into the second storage tank 130, the inside of the second storage tank 130 becomes a positive pressure state, and the dust D is returned to the return pipe 140. It is also possible to obtain the effect that it becomes easier to send to.

When the dust D is delivered from the second storage tank 130 to the return pipe 140, the second dust delivery stage ends and the next dust return stage is started. At this time, when the amount of dust D collected in the dust suction stage is large and a large amount of dust D is stored in the second storage tank 130 in the first dust delivery stage, as shown in FIG. Even if the two valves 132 are opened, the entire amount of the dust D in the second storage tank 130 cannot be sent to the dust receiving part 140a, and part of the dust D enters the second storage tank 130 or the throttle part 141. may remain. Even in such a case, the second dust sending stage is finished while the second valve 132 is kept open, and the next dust returning stage is started. In addition, when the amount of collected dust D is small and the entire amount of dust D in the second storage tank 130 can be sent to the dust receiving part 140a, the second valve 132 is closed and the dust returning stage is started. may migrate.

Finally, the dust return stage will be described. In the dust return stage, as shown in FIG. 5, the compressed air jet means 150 jets the compressed air from the jet port 151a of the jet nozzle 151 to return the dust D in the dust receiver 140a to the mixing tank. As a result, the dust D can be vigorously returned to the mixing tank at once, so that the dust D can be prevented from adhering to the inside of the return pipe 140 .

If the amount of dust D collected in the dust suction stage is large and dust D remains in the second storage tank 130 or in the throttle section 141 even after the second dust delivery stage is completed, the above-described The second valve 132 remains open. Therefore, when the dust D in the dust receiving part 140a is returned to the mixing tank by the compressed air jetting means 150, as shown in FIG. D falls into the dust receiving portion 140a. Also at this time, the second storage tank dust adhesion suppressing means (the second vibration generating device 130a, the compressed air inflow means 130b, etc.) can be operated in the same manner as in the second dust sending stage described above. In this way, the dust D that sequentially falls into the dust receiving portion 140a is returned to the mixing tank by repeating the injection of compressed air by the compressed air injection means 150 a plurality of times. The number of times the compressed air ejecting means 150 ejects the compressed air can be changed according to the amount of dust D collected. If the amount of dust D varies from batch to batch, a detection means (not shown) capable of detecting the remaining amount of dust D in the second storage tank 130 or the return pipe 140 is provided, and compressed air is blown out. The number of times may be determined automatically. When the entire amount of dust D has been returned to the mixing tank, the dust return stage is completed.

As described above, in the dust collecting device 100 of the present invention, the second storage tank 130 is provided. The entire amount of dust in the first storage tank 120 can be discharged, and thereafter the first valve 122 can be maintained in a closed state. As a result, after the first dust delivery stage ends, the dust suction stage of the next operation cycle can be started at any time, so that working efficiency can be improved. In addition, in the dust return stage, the compressed air ejection means 150 can eject the compressed air multiple times while the second valve 132 is open, so that the entire amount of dust can be efficiently returned to the mixing tank 210. can be done. Therefore, the time required for one operation cycle of the dust recovery device 100 can be shortened. can also be increased.

In the dust collection device 100 of the present invention, the type of the first valve 122 is not particularly limited as long as it is an openable/closable valve capable of blocking dust. Such valves include butterfly valves, gate valves, ball valves, and the like. In the present embodiment, as the first valve 122, a butterfly valve is employed which is less likely to be clogged with powder in the movable portion and which allows the powder to pass through efficiently. The butterfly valve also has the advantage that it takes less time to open and close the valve, which shortens the time required for the operation cycle of the dust collector 100 . Similarly to the first valve 122, the second valve 132 is not particularly limited in type, but is a butterfly valve in this embodiment.

The shape of the second storage tank 130 is not particularly limited, but it is preferable that the inner wall surface of the second storage tank 130 has a shape with less unevenness because dust is less likely to remain on the inner wall of the second storage tank 130 . Therefore, the second storage tank 130 is preferably cylindrical or funnel-shaped. In this embodiment, the second storage tank 130 is cylindrical. Moreover, it is preferable that the capacity of the second storage tank 130 can be changed according to the amount of dust to be collected. As a method for realizing this, for example, a plurality of second storage tanks 130 having different capacities may be prepared so that they can be replaced with the dust collection device 100 . In addition, when the second storage tank 130 is formed in a tubular shape, the tubular portion may have a slidable double tubular structure, or a new tubular member may be connected to the tubular portion. So, the length of the second storage tank 130 may be changed.

When the second storage tank 130 is cylindrical, how much the second storage tank 130 should be tilted with respect to the direction of gravity depends on the installation environment of the dust collection device 100, and is not particularly limited. However, if the inclination is too large, there is a possibility that the dust will be difficult to be delivered from the second storage tank 130 . Therefore, the angle θ (not shown) formed between the axial centerline C (see FIG. 1) of the second storage tank 130 and the vertical direction is preferably 45 degrees or less. The angle θ is more preferably 30 degrees or less, and even more preferably 15 degrees or less. In this embodiment, the second storage tank 130 is installed so that the angle θ is approximately 0 degrees.

The shape of the connecting portion between the second storage tank 130 and the return pipe 140 is not particularly limited, and the second dust delivery port 131 may be extended downward as it is and connected to the return pipe 140 . However, if the connecting portion between the second storage tank 130 and the return pipe 140 becomes too thick, the compressed air ejected from the compressed air ejection means 150 into the return pipe 140 will flow into the second storage tank 130 side, Dust may not be sent efficiently to the mixed layer 210 . For this reason, in the dust recovery device 100 of the present embodiment, as already described, the connecting portion between the second storage tank 130 and the return pipe 140 is provided with the throttle portion 141 (the cross-sectional area in the 2, a portion smaller than the area of the dust delivery port 131) is provided. This makes it difficult for the compressed air jetted from the compressed air jetting means 150 to escape to the second storage tank 130 side. However, if the narrowed portion 141 is provided, there is a possibility that the dust will be less likely to be sent from the second storage tank 130 to the return pipe 140. Since the portion on the downstream side of the valve 132 is in a negative pressure state, dust can be smoothly sent from the second storage tank 130 to the return pipe 140 easily even if the throttle portion 141 is provided.

The ejection port 151a of the ejection nozzle 151 in the compressed air ejection means 150 is not particularly limited as long as it is arranged in the dust receiving portion 140a in the return pipe 140 or upstream thereof. However, if the jet port 151a is too far upstream from the dust receiving portion 140a, the compressed air jetted from the jet port 151a will disperse before hitting the dust, and the dust will be efficiently moved to the mixed layer 210 side. You may not be able to send it. On the other hand, if the ejection port 151a is positioned downstream of the dust receiving portion 140a, dust remains on the upstream side of the ejection port 151a when the compressed air is ejected from the ejection port 151a. Therefore, as shown in FIG. 2 and the like, it is preferable to dispose the ejection port 151a of the ejection nozzle 151 near the dust receiving portion 140a. As a result, the dust delivered to the dust receiving portion 140a can be efficiently delivered to the mixed layer 210 side.

The shape of the ejection nozzle 151 is also not particularly limited, but in this embodiment, as shown in FIG. I'm trying As a result, the compressed air is more vigorously ejected from the ejection port 151a, so that the dust can be sent to the mixed layer 210 more efficiently, and the dust can be more reliably adhered to the inside of the return pipe 140. can be prevented.

The type of the dust-generating part in which the dust is collected using the dust collecting device 100 of the present invention is not particularly limited, but usually it is a space part that is closed to some extent in the device, and powder is collected inside it. It is considered to be a part where dust can be scattered. Examples of such dust generating units include mixing tanks, storage tanks, raw material supply tanks, and carrier streams of various devices (mixers, conveyors, feeders, crushers, etc.) that handle solid raw materials including powders. roads, etc. The dust generating unit may be permanently installed in equipment such as a plant, or may be movable with moving means. If the dust generating section is movable, it is preferable that the dust collecting device 100 is also movable along with the dust generating section.

The dust collecting device 100 of the present invention can be introduced into any facility as long as it can generate powdery dust. Such facilities include, for example, factories that handle or manufacture powder (eg, ready-mixed concrete factories, recycling factories, crushed stone factories, food, cosmetics or pharmaceutical manufacturing factories, etc.). More specifically, the ready-mixed concrete plant includes a batcher plant for producing ready-mixed concrete, and the recycling plant includes an ash treatment and solidification plant.

REFERENCE SIGNS LIST 100 dust recovery device 110 suction pipe 120 first storage tank 120a first vibration generator 121 first dust delivery port 122 first valve 122a first drive means 130 second storage tank 130a second vibration generator 130b compressed air inflow means 131 Second dust delivery port 132 Second valve 132a Second drive means 140 Return pipe 140a Dust receiving part 141 Throttle part 150 Compressed air ejection means 151 Ejection nozzle 151a Ejection port 200 Mixer 210 Mixing tank 220 Input port D Dust

Claims (4)

A dust collecting device for collecting powdered dust scattered inside a dust generating part,
a suction pipe for sucking the dust in the dust generating portion together with the air;
a suction force generator that generates a suction force for the suction tube to suck dust;
a first storage tank for storing dust sucked by the suction pipe;
A first valve for opening and closing the first dust delivery port provided at the bottom of the first storage tank;
a second storage tank disposed below the first storage tank and having an upper portion connected to the first storage tank via a first valve;
a second valve for opening and closing the second dust delivery port provided at the bottom of the second storage tank;
The upstream side is connected to the second storage tank via the second valve, and the downstream end is connected to the dust generating part, and the dust sent out from the second storage tank is returned to the inside of the dust generating part. a tube;
Compressed air jetting means for sending the dust sent into the return pipe from the second storage tank to the dust generating part by jetting compressed air from upstream to downstream of the return pipe.
2. The dust collecting device according to claim 1, wherein a constriction is provided at a connecting portion between the second valve and the return pipe.
Claim that the ejection port of the ejection nozzle for ejecting compressed air into the return pipe in the compressed air ejection means is arranged in the vicinity of the point where the dust falls when the dust is sent out from the second storage tank in the return pipe. 3. The dust collection device according to 1 or 2.
4. The dust recovery apparatus according to claim 1, further comprising second storage tank dust adhesion suppression means for suppressing adhesion of dust to the inner wall of the second storage tank.

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