Suction nozzle

Abstract

This invention provides a suction nozzle that can reduce manufacturing costs compared to conventional methods and can suck up loose materials more efficiently than conventional methods. [Solution] The suction nozzle 18 for inserting its tip into a bulk material 2 and sucking up the bulk material 2 has a double-shell structure comprising an inner cylinder 20 whose inside is an intake passage 19 for the bulk material 2, and an outer cylinder 22 attached to the outer circumference of the inner cylinder 20 with an intake chamber 21 in between. An opening 23 for opening to the atmosphere is provided at the top of the intake chamber 21, while a plurality of communication holes 24 are formed in the tip side portion of the inner cylinder 20 to connect the inside and outside of the inner cylinder 20.

Description

[[TECHNICAL FIELD]]

[0001] The present invention relates to a suction nozzle. [[BACKGROUND ART]]

[0002] As an unloader for unloading various bulk cargoes such as grains loaded from a ship moored at a quay, a pneumatic unloader that performs unloading by inserting a suction nozzle into the bulk cargo, which is the cargo to be handled, and sucking the bulk cargo is known (see, for example, Patent Documents 1 and 2). As shown in FIG. 3, this type of pneumatic unloader 1 includes a receiver tank 3 into which bulk cargo 2 can be introduced, a vacuum blower 5 connected to the receiver tank 3 via an air pipe 4, a horizontal telescopic pipe 6 swingably connected to the receiver tank 3 and extending in the lateral direction, a bend pipe 7 connected to the tip end of the horizontal telescopic pipe 6 and bent downward, a vertical telescopic pipe 8 connected to the tip end of the bend pipe 7 and extending substantially vertically downward, and a suction nozzle 9 connected to the tip end of the vertical telescopic pipe 8 and inserted into the bulk cargo 2 loaded on a ship (not shown) to a predetermined depth.

[0003] Here, the horizontal telescopic pipe 6 includes a large-diameter pipe portion 6a connected to the receiver tank 3, and a small-diameter pipe portion 6b slidably inserted into the large-diameter pipe portion 6a, and is configured to be telescopic by relatively moving the large-diameter pipe portion 6a and the small-diameter pipe portion 6b.

[0004] Further, the vertical telescopic pipe 8 includes a large-diameter pipe portion 8a and a small-diameter pipe portion 8b slidably inserted into the large-diameter pipe portion 8a, and is configured to be telescopic by relatively moving the large-diameter pipe portion 8a and the small-diameter pipe portion 8b.

[0005] The bulk material 2, which is the cargo (object to be transported), is then sucked into the suction nozzle 9 along with air, and introduced into the receiver tank 3 via the vertical telescopic pipe 8, the bend pipe 7, and the horizontal telescopic pipe 6. From the bottom of the receiver tank 3, it is discharged to the chain conveyor 10 via a discharge machine 3a such as a rotary feeder, while the air separated from the bulk material 2 is sucked out from the air pipe 4 to the vacuum blower 5.

[0006] Here, the suction nozzle 9 will be described in detail with reference to the cross-sectional view in Figure 4. This type of suction nozzle 9 has a double-shell structure comprising an inner cylinder 12 which serves as an intake passage 11 for the bulk material 2, and an outer cylinder 14 attached to the outer circumference of the inner cylinder 12, separated by an intake chamber 13. An opening 15 for opening to the atmosphere is provided at the top of the intake chamber 13, and the bottom of the intake chamber 13 is open downwards. The tip of the outer cylinder 14 has a tapered shape, while the tip of the inner cylinder 12, which extends slightly further back than the tip of the outer cylinder 14, has a flared bell mouth shape. The tapered tip of the outer cylinder 14 and the flared tip of the inner cylinder 12 form a throttling passage 13a.

[0007] Furthermore, the openings 15 provided at the top of the intake chamber 13 are arranged in multiple locations (four locations in the figure) at equal intervals in the circumferential direction, as shown in Figure 5 in the view along the VV direction in Figure 4. Each of the openings 15 is equipped with a circumferentially slidable closing plate 17, and the opening area of ​​each opening 15 can be adjusted by sliding the closing plate 17 in the circumferential direction.

[0008] Then, when the tip of the suction nozzle 9 is inserted into the bulk material 2 and suction is performed using the inside of the inner cylinder 12 as the intake passage 11, air 16 is drawn in from the opening 15 at the top of the intake chamber 13 and descends. The air 16, whose flow velocity has been increased by the throttling passage 13a, is blown out from the bottom of the intake chamber 13, and as it folds upward along the bell-mouth-shaped curved surface of the inner cylinder 12, the bulk material 2 is carried up by the fold-back flow and sucked upward along with the flow of air 16, thereby lifting the bulk material 2. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Japanese Patent Publication No. 2016-23001 [Patent Document 2] Japanese Patent Publication No. 2016-23004 [Overview of the project] [Problems that the invention aims to solve]

[0010] However, in the conventional suction nozzle 9 described above, it was necessary to provide a bell mouth shape at the tip of the inner cylinder 12, which was time-consuming to manufacture, resulting in increased manufacturing costs. Moreover, in the case of an inner cylinder 12 with a bell mouth shape at the tip as in the conventional design, the air 16 is folded back along the curved surface of the bell mouth shape, making it easier for a flow of air 16 to rise along the inner circumferential surface of the inner cylinder 12. This makes it difficult to transport the bulk material 2 on the central side of the inner cylinder 12, thus making it difficult to efficiently suck up the bulk material 2.

[0011] This invention was made in view of the above-mentioned circumstances, and aims to provide a suction nozzle that can reduce manufacturing costs compared to conventional nozzles and can suck up loose materials more efficiently than conventional nozzles. [Means for solving the problem]

[0012] The present invention relates to a suction nozzle for inserting its tip into bulk material and sucking up the bulk material, characterized in that it has a double-shell structure comprising an inner cylinder whose interior serves as a suction passage for the bulk material, and an outer cylinder attached to the outer circumference of the inner cylinder with an intake chamber in between, and an opening for opening to the atmosphere is provided at the top of the intake chamber, while a plurality of communication holes are formed in the tip side portion of the inner cylinder to connect the inside and outside of the inner cylinder.

[0013] When using such a suction nozzle to suck up bulk material, the tip of the suction nozzle is inserted into the bulk material, and suction is performed using the inside of the inner cylinder as the suction passage. Air is drawn in from the opening at the top of the intake chamber and descends, flows into the center of the inner cylinder through each communication hole, and then folds back upward. Here, the bulk material is swept up by the foldback flow and is sucked up upward along with the airflow.

[0014] In other words, instead of creating a time-consuming bell mouth shape at the tip of the inner cylinder as in the conventional method, it is possible to achieve the same bulk material suction as before simply by performing a low-cost drilling process to form multiple communication holes that connect the inside and outside of the inner cylinder at the tip of the inner cylinder, thereby significantly reducing the manufacturing cost of the suction nozzle.

[0015] Moreover, in the case of an inner cylinder with a bell-mouth shape at the tip, as in the past, the air folds back along the curved surface of the bell-mouth shape, making it easy to form a flow that rises along the inner circumference of the inner cylinder. However, in the present invention, the air flowing in from each communication hole forms an upward flow that has a stirring effect on the bulk material all the way to the center of the inner cylinder. As a result, it becomes possible to efficiently suck up the bulk material at the center of the inner cylinder, which was previously difficult to transport, and the power consumption required to suck up the same amount of bulk material is less than in the past.

[0016] Furthermore, in carrying out the present invention in more detail, it is preferable to arrange the communication holes at the tip of the inner cylinder in a staggered pattern in the circumferential direction. In this way, the agitation effect of the bulk material by the air flowing into the inside of the inner cylinder from each communication hole is further enhanced, making it even easier to suck up the bulk material.

[0017] Furthermore, it is preferable to arrange the circumferentially arranged connecting holes in two or more rows vertically. In this way, the area where the bulk material is stirred by the air flowing into the inner cylinder expands upward, making it even easier to suck up the bulk material.

[0018] Preferably, a tapered shape is provided on the tip end side portion of the outer cylinder to narrow the lower region of the suction chamber. With this configuration, bulk materials that have entered the suction chamber through each communication hole can easily return to the inside of the inner cylinder through the communication holes again due to the tapered shape of the outer cylinder, and furthermore, since the lower end portion of the suction chamber is physically narrowed, the phenomenon that a large amount of bulk materials accumulate is also less likely to occur.

Effects of the Invention

[0019] According to the suction nozzle of the present invention, the manufacturing cost can be greatly reduced compared to the conventional case where a bell mouth shape is provided at the tip of the inner cylinder, and moreover, bulk materials can be sucked up more efficiently than in the conventional art, and the power consumption required for sucking up the same amount of bulk materials can be significantly reduced, thus achieving various excellent effects.

Brief Description of the Drawings

[0020] [Figure 1] It is a cross-sectional view showing one embodiment of the suction nozzle of the present invention. [Figure 2] It is an arrow view taken along the line II-II in Fig. 1. [Figure 3] It is an overall schematic diagram showing an example of a general pneumatic unloader. [Figure 4] It is a cross-sectional view showing an example of a conventional suction nozzle. [Figure 5] It is an arrow view taken along the line V-V in Fig. 4.

Mode for Carrying Out the Invention

[0021] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0022] Figure 1 shows one embodiment of the present invention, illustrating a suction nozzle 18 connected to the tip of a vertical telescopic tube 8 in a pneumatic unloader 1, which was outlined in the figures above, and inserted to a predetermined depth into bulk material 2 loaded on a ship. It has a double-shell structure, similar to the conventional design, comprising an inner cylinder 20 that serves as an intake passage 19 for the bulk material 2, and an outer cylinder 22 attached to the outer circumference of the inner cylinder 20, separated by an intake chamber 21. However, a distinguishing feature is that an opening 23 for venting to the atmosphere is provided at the top of the intake chamber 21, while a plurality of communication holes 24 are formed at the tip side of the inner cylinder 20, connecting the inside and outside of the inner cylinder 20.

[0023] Furthermore, as shown in Figure 2 in the view along the line II-II in Figure 1, the openings 23 provided at the top of the intake chamber 13 are opened at multiple locations (four locations in the figure) in the circumferential direction at equal intervals, similar to the conventional example described earlier in Figure 5. Each of the openings 23 is provided with a circumferentially slidable closing plate 25, and the opening area of ​​each of the openings 23 can be adjusted by sliding the closing plate 25 in the circumferential direction.

[0024] Furthermore, in this embodiment in particular, the communication holes 24 at the tip of the inner cylinder 20 are arranged in a staggered pattern in the circumferential direction, and the communication holes 24 arranged in rows in the circumferential direction are arranged in two stages in the vertical direction. Moreover, the tip of the outer cylinder 22 has a tapered shape that narrows the lower region of the intake chamber 21.

[0025] Furthermore, the tip of the inner cylinder 20 and the tip of the outer cylinder are joined together and closed, and the intake chamber 13 communicates with the inside of the inner cylinder 20 only through the respective communication holes 24.

[0026] When using such a suction nozzle 18 to suck up the bulk material 2, the tip of the suction nozzle 18 is inserted into the bulk material 2, and suction is performed using the inside of the inner cylinder 20 as the suction passage 19. As a result, air 16 is drawn in from the opening 23 at the top of the intake chamber 21 and descends, flows into the center of the inner cylinder 20 through each communication hole 24, and then folds back upward. Here, the bulk material 2 is swept up by the foldback flow and is sucked up upward along with the flow of air 16.

[0027] In other words, instead of providing a time-consuming bell mouth shape at the tip of the inner cylinder 20 as in the conventional method, it is possible to achieve the same suction of bulk material 2 as before simply by performing a low-cost drilling process to form a plurality of communication holes 24 that connect the inside and outside of the inner cylinder 20 at the tip side of the inner cylinder 20, and the manufacturing cost of the suction nozzle 18 will be significantly reduced compared to the conventional method.

[0028] Moreover, in the case of an inner cylinder 20 with a bell-mouth shape at the tip, as in conventional designs, the air 16 is folded back along the curved surface of the bell-mouth shape, making it easy to form a flow that rises along the inner circumferential surface of the inner cylinder 20. However, in this embodiment, the air 16 flowing in from each communication hole 24 forms an upward flow that exerts a stirring effect on the bulk material 2 all the way to the center of the inner cylinder 20. As a result, it becomes possible to efficiently suck up the bulk material 2 on the center side of the inner cylinder 20, which was previously difficult to transport, and the power consumption required to suck up the same amount of bulk material 2 is reduced compared to conventional designs.

[0029] Furthermore, in this embodiment in particular, the communication holes 24 at the tip of the inner cylinder 20 are arranged in two stages, upper and lower, and each is arranged in a staggered pattern in the circumferential direction. This enhances the stirring effect of the bulk material 2 by the air 16 flowing into the inside of the inner cylinder 20 from each communication hole 24, and expands the stirring area of ​​the bulk material 2 by the air 16 flowing into the inside of the inner cylinder 20 upwards, resulting in the effect of making it even easier to suck up the bulk material 2.

[0030] Furthermore, by giving the tip portion of the outer cylinder 22 a tapered shape, the lower region of the intake chamber 21 is narrowed. This makes it easier for loose material 2 that has entered the intake chamber 21 through each communication hole 24 to return to the inside of the inner cylinder 20 through the communication holes 24 again due to the tapered shape of the outer cylinder 22. In addition, the physical narrowing of the lower end of the intake chamber 21 makes it less likely for a large amount of loose material 2 to accumulate.

[0031] As explained above, this embodiment allows for a significant reduction in manufacturing costs compared to the conventional method of providing a bell-mouth shape at the tip of the inner cylinder 20. Furthermore, it enables more efficient suction of the bulk material 2 than conventional methods, significantly reducing the power consumption required to suction the same amount of bulk material 2.

[0032] Furthermore, the suction nozzle of the present invention is not limited to the embodiments described above, and may be used with suction equipment other than pneumatic unloaders. In addition, the communication hole can be any opening shape other than a perfect circle as shown in the figure, such as an ellipse, rectangle, or triangle. It can also be configured with three or more stages in the vertical direction, or as a single stage. Of course, various modifications can be made without departing from the spirit of the present invention. [Explanation of Symbols]

[0033] 2 Loose items 16 Air 18 Suction nozzle 19 Suction passage 20 Inner cylinder 21 Intake chamber 22 Outer cylinder 23 Opening 24 Communication hole

Claims

1. A suction nozzle for inserting its tip into bulk material and sucking up the bulk material, comprising a double-shell structure with an inner cylinder that serves as a suction passage for the bulk material and an outer cylinder mounted on the outer circumference of the inner cylinder separated by an intake chamber, wherein an opening for opening to the atmosphere is provided at the top of the intake chamber, and a plurality of communication holes are formed in the tip portion of the inner cylinder that connect the inside and outside of the inner cylinder.

2. The suction nozzle according to claim 1, wherein the communication holes in the tip portion of the inner cylinder are arranged in a staggered pattern in the circumferential direction.

3. A suction nozzle according to claim 1 or 2, wherein two or more rows of communication holes arranged in the vertical direction are arranged in the vertical direction.

4. The suction nozzle according to claim 1 or 2, wherein the tip portion of the outer cylinder is given a tapered shape to narrow the lower region of the intake chamber.

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