Pneumatic Unloader

Abstract

To reduce maintenance frequency by eliminating clearance adjustment work.SOLUTION: A pneumatic unloader comprises: first and second outlet passages O1, O2 that are branched from an outlet portion 31 of a receiver tank 2; first and second slide gates G1, G2 provided in parallel with the first and second outlet passages, respectively; a switching damper 51 provided at a branch portion J of the first and second outlet passages and switchable between a first position P1 and a second position P2; a first level sensor S1 including lower and upper first level sensors S1L, S1H detecting the presence or absence of a load; a second level sensor S2L including lower and upper second level sensors S2L, S2H; and a control device E controlling the first and second slide gates and the switching damper on the basis of detection results of the first and second level sensors. The control device controls the first and second slide gates in such a way as to open and close the first and second slide gates alternately.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a pneumatic unloader.

Background Art

[0002] Generally, in a port, a pneumatic unloader is installed to lift and discharge goods such as grains transported by ships, which are bulk goods.

[0003] This pneumatic unloader is equipped with a rotary feeder to discharge (cut off) the lifted goods at a substantially constant flow rate. The rotary feeder is designed to efficiently discharge the goods from the vacuum side to the atmosphere side while minimizing air leakage by adjusting the gap between the blades at the tip of the rotor and the side cover and the casing.

[0004] By attaching bolts inserted into the long holes of the blades to the rotor, the position of the blades and the gap can be adjusted. When the blades wear due to long-term use, the gap increases, the air leakage amount increases, and the efficiency decreases. Therefore, in such a case, an adjustment is made to shift the mounting position of the blades to reduce the gap.

Prior Art Documents

Patent Documents

[0005] [[ID=z29]]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, rotary feeders present a problem due to the adjustment and maintenance required as blades wear down. When the blades wear down, their position needs to be adjusted, and eventually, the blades need to be replaced. These maintenance tasks must be performed in the cramped space on the unloader machine. In addition, rotary feeders are sometimes transported to the factory for maintenance, in which case the rotary feeder must be removed in the cramped space on the unloader machine.

[0007] Furthermore, even if the gaps are adjusted, air leakage is unavoidable due to the inherent structure, which could negatively impact the efficiency of the unloader.

[0008] Therefore, this disclosure was conceived in view of these circumstances, and one of its purposes is to provide a pneumatic unloader that can reduce the frequency of maintenance by eliminating the need for gap adjustment work.

[0009] Another object of this disclosure is to provide a pneumatic unloader that can reduce the amount of leaked air by reducing the gap and improve efficiency. [Means for solving the problem]

[0010] According to one aspect of this disclosure, A receiver tank for storing the sucked-in load, A first outlet passage and a second outlet passage are provided branching off from the outlet of the receiver tank, A first slide gate and a second slide gate are provided in parallel to the first exit passage and the second exit passage, respectively. A switching damper provided at the branching point of the first and second exit passages, which is switchable between a first position that guides the load toward the first slide gate and a second position that guides the load toward the second slide gate, A first level sensor for detecting the presence or absence of a load at a position between the first slide gate and the switching damper, comprising a first level sensor including a lower first level sensor and an upper first level sensor, A second level sensor for detecting the presence or absence of a load at a position between the second slide gate and the switching damper, comprising a lower second level sensor and an upper second level sensor, A control device that controls the first slide gate, the second slide gate, and the switching damper based on the detection results of the first level sensor and the second level sensor, Equipped with, The control device controls the first slide gate and the second slide gate to alternately open and close them. A pneumatic unloader is provided, characterized by the following:

[0011] Preferably, the control device is With the first slide gate fully closed, the switching damper is switched to the first position. Subsequently, when the upper first level sensor detects a load, the switching damper is switched to the second position with the second slide gate fully closed, and the first slide gate is opened.

[0012] Preferably, the control device then closes the first slide gate when the lower first level sensor no longer detects a load.

[0013] According to other aspects of this disclosure, A receiver tank for storing the sucked-in load, A first slide gate and a second slide gate are provided in series from below at the outlet of the receiver tank, A level sensor for detecting the presence or absence of a load at a position between the first slide gate and the second slide gate, comprising a lower level sensor and an upper level sensor, A control device that controls the first slide gate and the second slide gate based on the detection result of the level sensor, Equipped with, The control device controls the first slide gate and the second slide gate so as to alternately open and close the first slide gate and the second slide gate. A pneumatic unloader is provided, which is characterized by the above.

[0014] Preferably, the control device opens the second slide gate while the first slide gate is fully closed, and then, when the upper level sensor detects a load, closes the second slide gate completely and then opens the first slide gate.

[0015] Preferably, the control device then opens the second slide gate after closing the first slide gate completely when the lower level sensor no longer detects a load.

Advantages of the Invention

[0016] According to the present disclosure, the maintenance frequency can be reduced by eliminating the work of gap adjustment. Also, the gap can be reduced to decrease the amount of leaked air and improve the efficiency.

Brief Description of the Drawings

[0017] [Figure 1] It is a schematic diagram of a pneumatic unloader according to an embodiment of the present disclosure. [Figure 2] It is a side cross-sectional view showing the feeding device of this embodiment. [Figure 3] It is a plan view showing a fixed gate member. [Figure 4] It is a plan view showing a movable gate member. ' [Figure 5] It is a plan view showing the first slide gate when fully opened. [[ID=4--2]] [Figure 6] It is a side cross-sectional view showing the first slide gate when fully opened. [Figure 7] It is a side cross-sectional view showing the first slide gate when fully closed. [Figure 8] It is a side cross-sectional view showing the first slide gate when half-opened. [Figure 9] This is a flowchart showing the control details in the feeding device. [Figure 10] This is a side cross-sectional view showing a feeding device of another embodiment. [Figure 11] This flowchart shows the control details in a feeding device of another embodiment. [Modes for carrying out the invention]

[0018] The embodiments of this disclosure will be described below with reference to the attached drawings. It should be noted that this disclosure is not limited to the embodiments described below.

[0019] As shown in Figure 1, a ship S is moored in the harbor, carrying cargo B, such as grain, in its cargo hold K. A pneumatic unloader (hereinafter simply referred to as "unloader") 100 is installed on the harbor's quay Q to suck up and unload the cargo B stored in the cargo hold K. For convenience, the directions of front, back, left, right, up, and down are defined as shown in the figure.

[0020] A pair of rails R are installed along the quay Q, and the unloader 100 is equipped with a traveling frame 1 that can travel on these rails R. The unloader 100 is also equipped with a receiver tank 2 that can rotate on the traveling frame 1. The receiver tank 2 can rotate around a pivot axis C1 that extends vertically relative to the traveling frame 1 as shown by arrow a.

[0021] One end of an air suction pipe 3 is connected to the top of the receiver tank 2, and the other end of the air suction pipe 3 is connected to a vacuum pump 4, which is, for example, a Roots blower. The vacuum pump 4 is installed in a machine room 5 connected to the receiver tank 2.

[0022] The base end of a horizontally extending pipe 6 is connected via a ball joint 19 to the inlet 35 (see Figure 2), which is the inlet for the load B of the receiver tank 2. The horizontal pipe 6 is extendable and retractable in its longitudinal direction as indicated by arrow b, allowing adjustment of the position of the nozzle 7, which is the suction port for the load B, in the horizontal direction or along the longitudinal direction of the horizontal pipe.

[0023] The receiver tank 2 has a boom 8, indicated by a dashed line, attached to its base so as to be able to be raised and lowered as shown by arrow c. The horizontal pipe 6 is attached along the boom 8 and is able to be raised and lowered together with the boom 8. In the illustrated example, the horizontal pipe 6 and boom 8 extend toward the sea side or toward the ship S side (forward side).

[0024] The base end of a curved pipe 9, which is bent downwards at a 90° angle, is integrally attached to the tip of the horizontal pipe 6. The base or upper end of a vertical pipe 10, which extends vertically, is rotatably connected to the tip of the curved pipe 9 via a swing joint 11, as indicated by arrow d.

[0025] During cargo handling operations, the vertical pipe 10 is inserted into the cargo hold K through the hatch H of the ship S. The vertical pipe 10 is extendable and retractable in its longitudinal direction as indicated by arrow e, allowing the height of the nozzle 7 to be adjusted according to the height of the cargo B or the ship S.

[0026] A nozzle 7 is attached to the tip or lower end of the vertical pipe 10. The nozzle 7 approaches or comes into contact with the cargo B in the cargo hold K to suck up the cargo B in the cargo hold K.

[0027] To allow for fine adjustment of the position and orientation of the nozzle 7, the upper and lower ends of the vertical tube 10 are formed by flexible tubes 12.

[0028] A filter, or bag filter 13, is provided at the upper end of the receiver tank 2 to prevent load B from being sucked into the vacuum pump 4.

[0029] Furthermore, a chute 14 is provided below the receiver tank 2, which is used to drop and supply the load B discharged from the outlet of the receiver tank 2 to one end of the in-machine conveyor 15.

[0030] A ground chute 16 is provided projecting downward from the other end of the in-machine conveyor 15. The load B that has been transported to the other end of the in-machine conveyor 15 is dropped and supplied to the ground conveyor 17 through the ground chute 16. In this embodiment, multiple (two) ground chutes 16 are provided to correspond to multiple (two) ground conveyors 17. A slide gate 18 is provided at the upper end of each ground chute 16, allowing selection of the ground chute 16 to be used for supplying load B to the ground conveyor 17.

[0031] Furthermore, the chute 14 and the internal conveyor 15 are installed on the side of the travel frame 1 and do not rotate together with the receiver tank 2. The ground chute 16 may be reduced to one, and the slide gate 18 may be omitted.

[0032] Conventionally, a rotary feeder, which serves as a vacuum dispensing or feeding device, is installed in the middle of the chute 14. This rotary feeder controls the discharge flow rate of load B to the in-machine conveyor 15 (the amount of load B discharged per unit time) to be approximately constant, and also separates the vacuum side from the atmospheric side. That is, the area above the rotary feeder is the vacuum side, and the area below it is the atmospheric side.

[0033] However, using a rotary feeder presents the aforementioned challenges, namely the troublesome maintenance required and reduced efficiency due to gaps.

[0034] Therefore, this embodiment solves the above problem by installing a different feeding device in place of the rotary feeder.

[0035] Figure 2 shows the dispensing device of this embodiment. The dispensing device 30 comprises the above-mentioned receiver tank 2 for storing the sucked load B, a first outlet passage O1 and a second outlet passage O2 branched off from the outlet 31 of the receiver tank 2, a first slide gate G1 and a second slide gate G2 provided in parallel to the first outlet passage O1 and the second outlet passage O2, respectively, and a switching damper 51 provided at the branching point J of the first outlet passage O1 and the second outlet passage O3.

[0036] The dispensing device 30 also includes a first level sensor S1 for detecting the presence or absence of load B at a position between the first slide gate G1 and the switching damper 51, a second level sensor S2 for detecting the presence or absence of load B at a position between the second slide gate G2 and the switching damper 51, and a control device E that controls the first slide gate G1, the second slide gate G2, and the switching damper 51 based on the detection results of the first level sensor S1 and the second level sensor S2.

[0037] The first level sensor S1 includes a lower first level sensor S1L and an upper first level sensor S1H. The second level sensor S2 includes a lower second level sensor S2L and an upper second level sensor S2H.

[0038] The control device E controls the first slide gate G1 and the second slide gate G2 to alternately open and close them.

[0039] The following describes each part in detail. The receiver tank 2 is a vertically elongated cylindrical container having a central axis C2 that is coaxial with the pivot axis C1. Hereinafter, the axial, radial, and circumferential directions with respect to the central axis C2 will simply be referred to as the axial, radial, and circumferential directions.

[0040] The receiver tank 2 has a main cylindrical section 32 with a constant radius and a tapered cylindrical section 33 connected to the lower end of the main cylindrical section 32, which gradually decreases in diameter as it extends downward. An inlet 35 for supplying or depositing load B into the receiver tank 2 is connected at a predetermined height position of the main cylindrical section 32, extending diagonally downward. This inlet 35 is connected to a ball joint 19 shown in Figure 1, and receives load B from the ball joint 19.

[0041] The inlet ends of the first outlet passage O1 and the second outlet passage O2 are connected to the lower end of the tapered cylindrical section 33, forming a branching section J. The first outlet passage O1 and the second outlet passage O2 are located downstream of the tapered cylindrical section 33 in the flow direction of the load B. Therefore, the load B falling through the tapered cylindrical section 33 is supplied to one of the first outlet passage O1 and the second outlet passage O2, which are opened by the switching damper 51. The configurations of the first outlet passage O1 side and the second outlet passage O2 side are symmetrical with respect to the central axis C2. For this reason, only the first outlet passage O1 side will be described in detail below.

[0042] The first outlet passage O1 is formed in a generally elongated shape by a pipe or duct with a circular cross-section. However, the cross-sectional shape of the first outlet passage O1 is arbitrary and may be, for example, rectangular. The inlet end or upper end of the first outlet passage O1 is connected perpendicularly to the tapered cylindrical section 33. The first outlet passage O1 extends diagonally downward from its inlet end toward the outlet side, away from the central axis C2, and then bends to extend vertically downward. Thus, the first outlet passage O1 has an upper inclined section 52 and a lower vertical section 53. The outlet end or lower end of the first outlet passage O1 (not shown) is connected in series to the aforementioned chute 14.

[0043] The first slide gate G1 is provided in the vertical section 53. The first slide gate G1 opens and closes the vertical section 53 to allow or block the flow of load.

[0044] Figure 2 is a side cross-sectional view showing the first slide gate G1 when fully closed. Figure 3 is a plan view showing the fixed gate member 37, which is a component of the first slide gate G1. Figure 4 is a plan view showing the movable gate member 38, which is a component of the first slide gate G1.

[0045] As shown in Figures 2 to 4, the first slide gate G1 comprises a fixed gate member 37 and a movable gate member 38. The fixed gate member 37 has a plurality of (five in the illustrated example) lattices 39 extending in a direction perpendicular to the axial direction, i.e., in the horizontal direction. These lattices 39 are arranged parallel to each other and extend to traverse the vertical section 53. In this embodiment, a circular ring-shaped rim 40 is attached to the inner circumferential surface of the vertical section 53, and both ends of each lattice 39 are fixed to this rim 40. However, the rim 40 may be omitted, and both ends of each lattice 39 may be directly fixed to the vertical section 53. A total of several (six in the illustrated example) fixed slits 41 for passing the load B are formed between each lattice 39.

[0046] The upper surface of the lattice 39 is inclined to allow the load B that falls there to slide smoothly into the fixing slit 41, and is specifically formed in a mountain-shaped cross-section. In this embodiment, the cross-sectional shape of the lattice 39 is a home plate-shaped pentagon, and the lattice 39 has a solid structure. However, the configuration and shape of the lattice 39 are not limited to this, and for example, the lattice 39 may be formed from a plate material with an L-shaped cross-section (e.g., L-shaped steel) and arranged so that the upper surface is mountain-shaped.

[0047] The movable gate member 38 is formed from a flat plate material that is rectangular in plan view, and is superimposed on the lower surface of the fixed gate member 37 so as to be slidable in the front-rear direction as indicated by arrow f. Support members (not shown) are provided on the vertical portion 53 to slidably support the left and right side edges of the movable gate member 38. The movable gate member 38 has a plurality of (six in the illustrated example) movable slits 42 that fully open the fixed slit 41 when the first slide gate G1 is fully open. Between the movable slits 42, there is a closing portion 43 that fully closes the fixed slit 41 when the first slide gate G1 is fully closed.

[0048] The lattice 39, fixed slit 41, movable slit 42, and closing part 43 extend in a direction perpendicular to the sliding direction f.

[0049] The width W1 of the movable slit 42 in the sliding direction f is equal to the width W2 of the fixed slit 41. The width W3 of the closing portion 43 is also equal to the width W4 of the lattice 39. In this embodiment, W1=W2=W3=W4. However, these dimensions can be set arbitrarily.

[0050] The first slide gate G1 is equipped with an actuator 44, such as a hydraulic cylinder, that drives the movable gate member 38. This actuator 44 is electrically connected to a control device E. When the actuator 44 operates according to a command from the control device E, the movable gate member 38 slides in the sliding direction f, and is opened and closed.

[0051] Figures 5 and 6 are a plan view and a side cross-sectional view showing the first slide gate G1 when fully open. At this time, the fixed slit 41 and the movable slit 42 are aligned perfectly in the vertical or up-and-down direction with the same width, and the fixed slit 41 is completely opened by the movable slit 42. Also at this time, the lattice 39 and the closing part 43 are aligned perfectly in the vertical or up-and-down direction with the same width.

[0052] Figure 7 is a side cross-sectional view showing the first slide gate G1 when fully closed. At this time, the movable gate member 38 slides further back than when fully open. The closing part 43 is aligned perfectly with the fixed slit 41 in the vertical direction with the same width, and the fixed slit 41 is completely closed by the closing part 43 or the movable gate member 38. At this time, the movable slit 42 is also aligned perfectly with the lattice 39 in the vertical direction with the same width.

[0053] When fully closed, the fixed slit 41 is completely closed, and the movable gate member 38 is brought into close contact with the fixed gate member 37 by suction. This reduces the gap between the fixed gate member 37 and the movable gate member 38, thereby suppressing air leakage through the first slide gate G1.

[0054] Incidentally, the first slide gate G1 can also be set to a half-open or intermediate opening, as shown in Figure 8. Figure 8 is a side cross-sectional view showing the first slide gate G1 in the half-open or intermediate opening position. In this case, the movable gate member 38 is positioned between the fully open and fully closed positions. A portion of the fixed slit 41 in the width direction is opened by the movable slit 42, but the remaining portion of the fixed slit 41 is closed by the closing part 43 or the movable gate member 38, leaving the fixed slit 41 in a half-open state.

[0055] The second exit passage O2 is configured symmetrically with respect to the first exit passage O1, with respect to the central axis C2. The second slide gate G2 is configured similarly to the first slide gate G1 and is installed in the vertical portion 53 of the second exit passage O2, at the same height as the first slide gate G1.

[0056] The switching damper 51 has a pivot shaft 54 ​​and a closing plate 55 that can rotate around the pivot shaft 54 ​​as shown by arrow i. The closing plate 55 is rotatable between a first position P1 that opens the inlet end of the first outlet passage O1 and airtightly closes the inlet end of the second outlet passage O2, and a second position P2 that opens the inlet end of the second outlet passage O2 and airtightly closes the inlet end of the first outlet passage O1.

[0057] When the closing plate 55, or switching damper 51, is in the first position P1, the load B supplied into the receiver tank 2 is guided only to the first outlet passage O1, i.e., the first slide gate G1 side, and flow to the second outlet passage O2, i.e., the second slide gate G2 side is blocked. Conversely, when the closing plate 55, or switching damper 51, is in the second position P2, the load B supplied into the receiver tank 2 is guided only to the second outlet passage O2, i.e., the second slide gate G2 side, and flow to the first outlet passage O1, i.e., the first slide gate G1 side is blocked.

[0058] Although a rotary-type switching damper 51 is shown here, the type of switching damper is arbitrary and may be a sliding type, for example.

[0059] The lower first level sensor S1L and the upper first level sensor S1H are located downstream of the switching damper 51 and upstream of the first slide gate G1, and are positioned in the vertical section 53. The lower first level sensor S1L is located above the first slide gate G1 and at a height near it. The upper first level sensor S1H is located above the lower first level sensor S1L and at a height at the same height as or slightly lower than the pivot axis 54.

[0060] The lower first level sensor S1L and the upper first level sensor S1H are configured, for example, as well-known paddle-type level sensors. They turn on when load B is detected (when load B is at the height of the level sensor) and turn off when load B is not detected (when load B is not at the height of the level sensor). Note that the lower first level sensor S1L and the upper first level sensor S1H may be configured as sensors other than paddle-type level sensors.

[0061] The same applies to the lower second level sensor S2L and the upper second level sensor S2H.

[0062] The control device E is composed of a well-known control unit equipped with a CPU, memory, etc., and is electrically connected to the first and second slide gates G1 and G2, and to the respective level sensors S1L, S1H, S2L, and S2H.

[0063] The feed device 30 has a gate position sensor 45 for each slide gate to detect the actual position of the movable gate member 38. The gate position sensor 45 is configured, for example, by a well-known encoder. These gate position sensors 45 are also electrically connected to the control device E. Based on the signals from the gate position sensors 45, the control device E controls the position of the movable gate member 38 and, consequently, the opening degree of the slide gate.

[0064] Next, the operation of the unloader 100 and the feed device 30 will be explained.

[0065] As shown in Figure 1, during cargo handling operations of the unloader 100, the vacuum pump 4 is activated, and cargo B in the cargo hold K is sucked in through the nozzle 7. This sucked-in cargo B rises through the vertical pipe 10 and reaches the horizontal pipe 6 through the curved pipe 9. It then moves through the horizontal pipe 6 and is fed into the receiver tank 2 through the input port 35.

[0066] After that, load B passes through the dispensing device 30, at which point the flow rate of load B is controlled. Load B discharged from the dispensing device 30 is sent to the ground conveyor 17 via the chute 14, the in-machine conveyor 15, and the ground chute 16.

[0067] Inside the receiver tank 2, the load B introduced from the inlet 35 falls as indicated by arrow g, and the airflow rises as indicated by arrow h, separating the load B from the airflow. The rising airflow passes through the bag filter 13, where any dust contained in the airflow is filtered out. After this, the airflow reaches the vacuum pump 4 and is released into the atmosphere through the exhaust pipe.

[0068] During these cargo handling operations, the first and second slide gates G1 and G2 are controlled by the control device E as follows. An example of the control is described below.

[0069] Figure 9 is a flowchart showing the normal operation and control of the dispensing device 30. The symbol Sn (where n is an integer) represents the step number. Here, we assume that the initial state (S0) is one in which the receiver tank 2 and the first and second outlet passages O1 and O2 are empty (no load B), and therefore the level sensors S1L, S1H, S2L, and S2H are off, the first and second slide gates G1 and G2 are fully closed, and the switching damper 51 is in the first position P1.

[0070] From this initial state, cargo handling operations begin, and when cargo B is supplied into the receiver tank 2, cargo B is guided to the first outlet passage O1 and accumulates on the first slide gate G1. First, the lower first level sensor S1L turns on (S1), and then the upper first level sensor S1H turns on (S2).

[0071] Then, the switching damper 51 is switched to the second position P2, and the first slide gate G1 is opened, especially fully opened (S3). As a result, the load B supplied into the receiver tank 2 is guided to the second slide gate G2 side and accumulates on the second slide gate G2. The load B that had accumulated on the first slide gate G1 passes through the first slide gate G1 and falls out onto the in-machine conveyor 15.

[0072] Subsequently, the level of load B decreases within the first exit passage O1, and after the upper first level sensor S1H turns off, the lower first level sensor S1L also turns off (S4). Then, the first slide gate G1 is fully closed (S5).

[0073] On the other hand, within the second exit passage O2, the level of load B rises, the lower second level sensor S2L turns on, and then the upper second level sensor S2H turns on (S6).

[0074] Then, the switching damper 51 is switched to the first position P1, and the second slide gate G2 opens, especially fully (S7). As a result, the load B supplied into the receiver tank 2 is guided back to the first slide gate G1 side and accumulates on the first slide gate G1. Also, the load B that had accumulated on the second slide gate G2 falls through the second slide gate G2 and is discharged onto the in-machine conveyor 15.

[0075] Subsequently, the level of load B decreases within the second exit passage O2, and after the upper second level sensor S2H turns off, the lower second level sensor S2L also turns off (S8). Then, the second slide gate G2 is fully closed (S9).

[0076] On the other hand, as the level of load B rises within the first exit passage O1, the process returns to step S2 and the aforementioned control is repeated.

[0077] In this manner, the control device E alternately opens and closes the first slide gate G1 and the second slide gate G2. The control device E also switches the position of the switching damper 51 in accordance with the switching of the opening and closing of the first slide gate G1 and the second slide gate G2.

[0078] In this embodiment, when load B is accumulated in either the first outlet passage O1 or the second outlet passage O2, the corresponding first slide gate G1 or second slide gate G2 closes that passage, and the switching damper 51 closes the other passage. Thus, leakage of air from the atmospheric side (downward side) to the vacuum side (upward side) of the feeding device 30 can be prevented. Therefore, compared to conventional unloaders using rotary feeders, the gap can be reduced (substantially eliminated), the amount of leaked air can be reduced (substantially eliminated), and efficiency (e.g., the energy efficiency of the unloader) can be improved.

[0079] Furthermore, even when the load B is being discharged from either the first outlet passage O1 or the second outlet passage O2, the switching damper 51 closes one of the passages, and the other of the first slide gate G1 and the second slide gate G2 closes the other passage. Therefore, even in this case, air leakage through the dispensing device 30 can be prevented, and efficiency can be improved.

[0080] Furthermore, gap adjustment is not required for each slide gate G1 and G2. Therefore, the need for gap adjustment work can be eliminated, reducing the frequency of maintenance. This also significantly reduces the burden of maintenance.

[0081] [Other embodiments] Next, other embodiments of the present disclosure will be described. Parts identical to those in the basic embodiment described above are denoted by the same reference numerals in the figures and their descriptions are omitted. The following will primarily describe the differences from the basic embodiment.

[0082] Figure 10 shows the dispensing device of this embodiment. The dispensing device 30 comprises the above-mentioned receiver tank 2 for storing the sucked load B, and a first slide gate G1 and a second slide gate G2 which are provided in series from below at the outlet portion 31 of the receiver tank 2.

[0083] The dispensing device 30 also includes a level sensor S for detecting the presence or absence of load B at a position between the first slide gate G1 and the second slide gate G2, and a control device E for controlling the first slide gate G1 and the second slide gate G2 based on the detection result of the level sensor S. The level sensor S includes a lower level sensor SL and an upper level sensor SH.

[0084] The control device E controls the first slide gate G1 and the second slide gate G2 to alternately open and close them.

[0085] The following describes each part in detail. The receiver tank 2 is generally the same as described above, and has the same main cylinder section 32 and tapered cylinder section 33. An outlet cylinder section 61, which has a smaller diameter than the main cylinder section 32, a constant radius and extends vertically, is coaxially connected to the lower end of the tapered cylinder section 33. The outlet cylinder section 61 is formed by a pipe or duct with a circular cross-section. However, the cross-sectional shape of the outlet cylinder section 61 is arbitrary and may be, for example, square. The outlet end or lower end of the outlet cylinder section 61, which is not shown, is connected in series to the chute 14 described above.

[0086] The first slide gate G1 and the second slide gate G2 are provided in the outlet cylinder 61. These slide gates G1 and G2 themselves are the same as in the basic embodiment described above, and open and close the outlet cylinder 61 to allow or block the flow of load. The second slide gate G2 is located at a predetermined distance above the first slide gate G1.

[0087] The lower level sensor SL is located above and near the height of the first slide gate G1. The upper level sensor SH is located above the lower level sensor SL and below and near the height of the second slide gate G2. These level sensors SL and SH are the same as in the basic embodiment described above and are switched on and off depending on the presence or absence of load B.

[0088] The control device E is the same as described above, and the gate position sensor 45 is also provided in the same manner as described above.

[0089] Next, the operation of the unloader 100 and the feed device 30 in this embodiment will be described.

[0090] During the unloading operation of the unloader 100, the first and second slide gates G1 and G2 are controlled by the control device E as follows. An example of the control is described below.

[0091] Figure 11 is a flowchart showing the normal operation and control of the dispensing device 30. Here, we assume that the initial state (S20) is that the receiver tank 2 is empty (no load B), therefore the level sensors SL and SH are off, the first slide gate G1 is fully closed, and the second slide gate G2 is open, especially fully open.

[0092] From this initial state, cargo handling operations begin, and as cargo B is supplied into the receiver tank 2, cargo B accumulates on the first slide gate G1. First, the lower level sensor SL turns on (S21), and then the upper level sensor SH turns on (S22).

[0093] First, the second slide gate G2 is fully closed (S23), and then the first slide gate G1 is opened, specifically fully opened (S24). As a result, the load B supplied into the receiver tank 2 accumulates on the second slide gate G2. The load B that had accumulated on the first slide gate G1 then passes through the first slide gate G1 and is discharged onto the in-machine conveyor 15.

[0094] Since the second slide gate G2 is fully closed before the first slide gate G1 is opened, it is possible to prevent both slide gates from opening simultaneously at the same time during the switching between opening and closing. Therefore, air leakage from the atmospheric side to the vacuum side can be prevented, and efficiency can be improved.

[0095] Subsequently, the level of load B accumulated on the first slide gate G1 decreases, the upper level sensor SH turns off, and then the lower level sensor SL turns off (S25). At this point, the first slide gate G1 is fully closed (S26).

[0096] Subsequently, the second slide gate G2 is fully opened (S27), and the load B that had been accumulated on the second slide gate G2 passes through the second slide gate G2 and falls, accumulating on the first slide gate G1.

[0097] In this way, the load B accumulates on the first slide gate G1 until the upper level sensor SH is turned on in step S22.

[0098] Since the first slide gate G1 is fully closed in step S26 before the second slide gate G2 is opened in step S27, it is possible to prevent both slide gates from opening instantaneously and simultaneously when switching between opening and closing, as described above. Therefore, air leakage from the atmospheric side to the vacuum side can be prevented, and efficiency can be improved.

[0099] Thus, in this embodiment as well, the control device E alternately opens and closes the first slide gate G1 and the second slide gate G2.

[0100] In this embodiment, when the first slide gate G1 is closed (fully closed), the first slide gate G1 itself prevents air leakage from the atmosphere to the vacuum. Also, when the first slide gate G1 is open (fully open), the second slide gate G2 closes to prevent air leakage from the atmosphere to the vacuum. Therefore, air leakage from the atmosphere to the vacuum can always be prevented. Compared to conventional unloaders using rotary feeders, the gap can be reduced (virtually eliminated), the amount of leaked air can be reduced (virtually eliminated), and efficiency (e.g., the energy efficiency of the unloader) can be improved.

[0101] Furthermore, gap adjustment is not required for each slide gate G1 and G2. Therefore, the need for gap adjustment work can be eliminated, reducing the frequency of maintenance. This also significantly reduces the burden of maintenance.

[0102] Although embodiments of the present disclosure have been described in detail above, various embodiments and modifications of the present disclosure are conceivable.

[0103] (1) In the above-described embodiment, the first and second slide gates G1 and G2 were always fully open when opened, but the invention is not limited to this, and they may be partially open as needed.

[0104] (2) In the first and second slide gates G1 and G2, the fixed gate member 37 may have a grid instead of multiple lattices 39. In the above embodiment, the fixed slit 41 and the movable slit 42 were rectangular or substantially rectangular in shape when viewed from above, but they may have other shapes such as circles.

[0105] The embodiments of this disclosure are not limited to those described above, but include any variations, applications, and equivalents encompassed within the spirit of this disclosure as defined by the claims. Therefore, this disclosure should not be constrained, but can be applied to any other art that falls within the scope of the spirit of this disclosure. [Explanation of Symbols]

[0106] 2 Receiver Tanks 31 Exit section 51 Switching damper 100 Pneumatic Unloader B cargo E Control device G1 First Slide Gate G2 2nd Slide Gate J branch O1 1st exit passage O2 2nd exit passage P1 1st position P2 2nd position S1 First level sensor S1L Lower first level sensor S1H Upper first level sensor S2 Second level sensor S2L Lower second level sensor S2H Upper second level sensor S level sensor SL lower level sensor SH Upper Level Sensor

Claims

1. A receiver tank for storing the sucked-in load, A first outlet passage and a second outlet passage are provided branching off from the outlet of the receiver tank, A first slide gate and a second slide gate are provided in parallel to the first exit passage and the second exit passage, respectively. A switching damper provided at the branching point of the first and second exit passages, which is switchable between a first position that guides the load toward the first slide gate and a second position that guides the load toward the second slide gate, A first level sensor for detecting the presence or absence of a load at a position between the first slide gate and the switching damper, comprising a first level sensor including a lower first level sensor and an upper first level sensor, A second level sensor for detecting the presence or absence of a load at a position between the second slide gate and the switching damper, comprising a lower second level sensor and an upper second level sensor, A control device that controls the first slide gate, the second slide gate, and the switching damper based on the detection results of the first level sensor and the second level sensor, Equipped with, The control device controls the first slide gate and the second slide gate so that they alternately open and close. The control device is With the first slide gate fully closed, the switching damper is switched to the first position. Subsequently, when the upper first level sensor detects a load, the switching damper is switched to the second position with the second slide gate fully closed, and the first slide gate is opened. The control device then closes the first slide gate when the lower first level sensor no longer detects a load. A pneumatic unloader characterized by the following features.

2. A receiver tank for storing the sucked-in load, A first slide gate and a second slide gate are provided in series from below at the outlet of the receiver tank, A level sensor for detecting the presence or absence of a load at a position between the first slide gate and the second slide gate, comprising a lower level sensor and an upper level sensor, A control device that controls the first slide gate and the second slide gate based on the detection result of the level sensor, Equipped with, The control device controls the first slide gate and the second slide gate so that they alternately open and close. The control device is With the first slide gate fully closed, the second slide gate is opened. Subsequently, when the upper level sensor detects a load, the second slide gate is fully closed, and then the first slide gate is opened. A pneumatic unloader characterized by the following features.

3. The control device then fully closes the first slide gate and opens the second slide gate when the lower level sensor no longer detects a load. The pneumatic unloader according to claim 2.

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