Pneumatic unloader

Abstract

To provide a pneumatic unloader which can prevent an operator's artificial error and realize an improvement in cargo handling efficiency and a constant control of the flow rate in spite of an operator's skill.SOLUTION: A pneumatic unloader 1, equipped with a vertical expansion pipe 8, equipped with a suction nozzle 9 at the tip to suspend, and carrying out cargo handling by sucking and transporting loose materials 2 out of the suction nozzle 9 by means of suction with a vacuum blower 5, comprises a capacity adjustment valve 11 which controls suction capacity by adjusting the auction amount of ambient air on the inlet side of the vacuum blower 5, a flowmeter 12 which measures the landing flow rate of the loose materials 2 sucked into the vertical expansion pipe 8, and a control device 13 which automatically controls the operation of opening the capacity adjustment valve 11 so that a suitable landing flow rate may be kept on the basis of a measured value of the flowmeter 12.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a pneumatic unloader. [Background technology]

[0002] A pneumatic unloader is known as an unloader that unloads various bulk materials such as grains loaded on ships anchored at a quay, and unloads the materials by inserting a suction nozzle into the bulk materials and sucking them in (see, for example, Patent Documents 1 and 2).

[0003] This type of pneumatic unloader is equipped with a horizontal telescopic pipe that is connected to a receiver tank located on the quay side and extends laterally, a bend pipe that is connected to the horizontal telescopic pipe and bends downward, a vertical telescopic pipe that is connected to the end of the bend pipe and extends almost vertically downward, and a suction nozzle that is connected to the end of the vertical telescopic pipe and can be inserted into the cargo, and unloads the cargo by sucking up loose items through the suction nozzle using the suction force of a vacuum blower. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2016-23001 A [Patent Document 2] JP 2016-23004 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, such conventional pneumatic unloaders were equipped with a capacity control valve that adjusted the amount of air sucked in at the inlet side of the vacuum blower, and the operator in the cab had to manually open and close the capacity control valve to improve loading efficiency and maintain a constant flow rate while monitoring the loading situation and the status of the rear equipment.This meant that there was a possibility of human error, and as the operation was largely based on experience, there was also a risk that the results would vary depending on the operator's skill.

[0006] In other words, when the capacity control valve is closed, the amount of air intake decreases and the suction force increases, thereby increasing the bulk lifting capacity, and when the capacity control valve is opened, the amount of air intake increases and the suction force decreases, thereby decreasing the bulk lifting capacity.However, if the capacity control valve is closed too much, there is a concern that excessive bulk material will be sucked in, which could slow down the processing of bulk material at the rear equipment, and conversely, if the valve is opened too much, bulk material will not be able to be sucked in efficiently, so the operator had to manually operate the opening of the capacity control valve appropriately depending on the loading situation and the situation of the rear equipment.

[0007] The present invention has been made in consideration of the above-mentioned situation, and aims to provide a pneumatic unloader that can avoid human error by the operator and achieve improved loading and unloading efficiency and constant flow rate control regardless of the operator's skill. [Means for solving the problem]

[0008] The present invention is a pneumatic unloader that is equipped with a vertical telescopic tube that is hung down with a suction nozzle at the tip, and performs loading and unloading by sucking and conveying bulk materials from the suction nozzle by suction using a vacuum blower, This pneumatic unloader is equipped with a capacity control valve that controls the suction capacity by adjusting the amount of air sucked in at the inlet side of the vacuum blower, a flow meter that measures the lifting flow rate of bulk materials sucked into the vertical telescopic pipe, and a control device that automatically controls the opening operation of the capacity control valve so that an appropriate lifting flow rate is maintained based on the measurement value of the flow meter.

[0009] Furthermore, it is preferable that the control device automatically controls the opening operation of the capacity control valve so as to close the capacity control valve when the measurement value of the flow meter is smaller than a set value, and to open the capacity control valve when the measurement value of the flow meter is greater than the set value. Effect of the Invention

[0010] According to the pneumatic unloader of the present invention, the opening operation of the capacity control valve after the operator has started to manually load bulk materials can be automatically controlled by a control device, thereby preventing human error by the operator and providing the excellent effects of easily improving loading efficiency and achieving constant flow rate control regardless of the operator's skill level. [Brief description of the drawings]

[0011] [Figure 1] 1 is an overall configuration diagram showing one embodiment of a pneumatic unloader of the present invention. FIG. [Diagram 2] 2 is a flow chart showing a specific procedure of automatic control in the control device of FIG. 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0013] Figures 1 and 2 show one embodiment of the present invention. First, the overall structure of a pneumatic unloader 1 in this embodiment will be described below with reference to Figure 1. This type of pneumatic unloader 1 comprises a receiver tank 3 into which bulk materials 2 can be introduced, a vacuum blower 5 connected to the receiver tank 3 via an air pipe 4, a horizontally telescopic pipe 6 which is swingably connected to the receiver tank 3 and extends laterally, a bend pipe 7 connected to the end of the horizontally telescopic pipe 6 and bent downward, a vertically telescopic pipe 8 connected to the end of the bend pipe 7 and extends downward approximately vertically, and a suction nozzle 9 connected to the end of the vertically telescopic pipe 8 and inserted to a predetermined depth into the bulk materials 2 loaded on a ship (not shown).

[0014] Here, the horizontal telescopic pipe 6 includes a large diameter pipe section 6a connected to the receiver tank 3 and a small diameter pipe section 6b slidably inserted into the large diameter pipe section 6a, and is configured to be telescopic by moving the large diameter pipe section 6a and the small diameter pipe section 6b relative to each other.

[0015] The vertical telescopic tube 8 includes the large diameter tube section 8a and a small diameter tube section 8b slidably inserted into the large diameter tube section 8a, and is configured to be telescopic by moving the large diameter tube section 8a and the small diameter tube section 8b relative to each other.

[0016] In this embodiment, bulk materials 2 as cargo (transported materials) are sucked into the suction nozzle 9 together with air, and then introduced into the receiver tank 3 via the vertical expansion tube 8, the bend tube 7, and the horizontal expansion tube 6. The bulk materials 2 separated from the air by the receiver tank 3 are supplied to the chain conveyor 10, while the air separated from the bulk materials 2 is sucked into the vacuum blower 5 through the air tube 4.

[0017] Furthermore, the symbol 11 in Figure 1 is a capacity control valve that adjusts the amount of air suction at the inlet side of the vacuum blower 5. When the capacity control valve 11 is closed, the amount of air suction decreases and the suction force increases, thereby increasing the lifting capacity of the bulk materials 2. When the capacity control valve 11 is opened, the amount of air suction increases and the suction force decreases, thereby decreasing the lifting capacity of the bulk materials 2.

[0018] Here, a flow meter 12 is installed on the upper part of the vertical telescopic pipe 8 to measure the lifting flow rate of the bulk material 2 sucked into the vertical telescopic pipe 8, and the opening operation of the capacity control valve 11 is automatically controlled by a control device 13 based on the flow rate value measured by the flow meter 12.

[0019] The flow meter 12 may be an existing sensor that measures the flow rate of the bulk material 2 using microwaves that utilize the Doppler effect, or a sensor that measures the flow rate of the bulk material 2 using ultrasound may be used.

[0020] The flow rate of the bulk material 2 is expressed by the following formula:

[0021] [Equation 1] Flow rate = flow velocity x density x nozzle cross-sectional area Therefore, it is also possible to use a flow meter 12 that can actually measure the density and flow velocity of the bulk material 2 and convert them into a flow rate.

[0022] Here, the control device 13 controls the capacity control valve 11 and other operating systems through manual operation performed by the driver using the driver's cab control console or radio controller, but when the driver selects automatic operation by operating a button or the like, as described above, the opening operation of the capacity control valve 11 is automatically controlled based on the flow rate value measured by the flow meter 12.

[0023] FIG. 2 is a flow chart explaining the specific steps of automatic control in the control device 13. First, in step S1, the unloading flow rate of bulk materials is measured by the flowmeter 12. In the next step S2, the flow rate value measured in step S1 is transferred to the control device 13 (PLC: Programmable Logic Controller). In the next step S3, it is determined whether the flow rate value is smaller than a preset value in the control device 13. If the answer is YES, the process proceeds to step S4, where control is executed to close the capacity control valve 11. After that, the process returns to step S1 and the same control procedure is repeated.

[0024] On the other hand, if the judgment in step S3 is NO, the process proceeds to step S5, where it is judged whether the flow rate value is greater than the set value in the control device 13; if the judgment is YES, the process proceeds to step S6, where control is executed to open the capacity control valve 11, and then the process returns to step S1 and the same control procedure is repeated.

[0025] If the judgment in step S5 is NO, the process proceeds to step S7, where measures are taken to maintain the opening of the capacity control valve 11 without operating the capacity control valve 11, and then the process returns to step S1 and the same control procedure is repeated.

[0026] That is, the control device 13 automatically controls so that the capacity control valve 11 is closed when the flow rate value (measured value) of the flow meter 12 is smaller than the set value, and the capacity control valve 11 is opened when the flow rate value of the flow meter 12 is greater than the set value.

[0027] Therefore, if the opening operation of the capacity control valve 11 after the start of loading and unloading work of bulk materials 2, which is manually performed by the operator, can be automatically controlled by the control device 13, human error by the operator can be avoided in advance, and improved loading and unloading efficiency and constant control of the flow rate can be easily achieved regardless of the operator's skill level.

[0028] Incidentally, the pneumatic unloader of the present invention is not limited to the above-mentioned embodiment, and it goes without saying that various modifications can be made without departing from the spirit and scope of the present invention. [Explanation of symbols]

[0029] 1 Pneumatic unloader 2 Loose items 5 Vacuum Blower 8 Vertical telescopic tube 9 Suction nozzle 11 Capacity control valve 12 Flow meter 13 Control device

Claims

1. A pneumatic unloader equipped with a vertical telescopic tube with a suction nozzle at the tip and hanging down, and performing cargo handling by sucking and conveying bulk materials through the suction nozzle by suction using a vacuum blower, A pneumatic unloader equipped with a capacity control valve that controls the suction capacity by adjusting the amount of air sucked in at the inlet side of the vacuum blower, a flow meter that measures the lifting flow rate of bulk materials sucked into the vertical telescopic pipe, and a control device that automatically controls the opening operation of the capacity control valve so that an appropriate lifting flow rate is maintained based on the measurement value of the flow meter.

2. A pneumatic unloader as described in claim 1, wherein the control device automatically controls the opening operation of the capacity control valve so as to close the capacity control valve when the measurement value of the flow meter is smaller than a set value, and to open the capacity control valve when the measurement value of the flow meter is greater than the set value.

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