JP3909141B2 - Air floating belt conveyor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a belt conveyor that conveys loose materials such as ore and coal, and relates to an air floating belt conveyor that travels in a state where the belt is floated by an air layer.
[0002]
[Prior art]
In recent years, as a belt conveyor for transporting loose materials such as ore and coal, an air levitation type in which a belt on which loose materials are placed is supported by a trough having an arc cross section and the belt is lifted by an air layer formed on the trough. Belt conveyors have been proposed.
[0003]
3 and 4 show an example of an air floating belt conveyor. In FIG. 3, the loop belt 1 is wound around pulleys 2 and 3 at both ends and runs around. As shown in detail in FIG. 4, this belt conveyor has a large number of air holes 17 arranged in the longitudinal direction at the center in the width direction of the troughs 12 and 13 having a circular cross section on the carrier side and the return side that support the belt 1. In addition, an air duct 16 communicating with each air hole 7 is provided on the lower surface of each trough 12, 13, and air is sent from the blower 18 to the air duct 16 so that the air duct 16 faces upward from the air hole 17 of each trough 12, 13. The air is ejected to the belt 1 to form an air layer between the belt 1 and the troughs 12 and 13 so that the belt 1 moving on the troughs 12 and 13 is levitated. The troughs 12 and 13 are fixed to the conveyor frame 14. A flow control valve 19 for controlling the amount of air blown from the air hole 17 is interposed in the middle of the air supply pipe connecting the blower 18 and the air duct 16.
[0004]
With this configuration, the air-floating belt conveyor can greatly reduce the resistance acting on the belt, and can reduce the driving load, as compared with the roller belt conveyor. Moreover, there is an advantage that noise and vibration can be reduced by eliminating the roller.
[0005]
[Problems to be solved by the invention]
By the way, in the above conventional air levitation type belt conveyor, as shown in FIG. 3, an air supply pipe is connected to a continuous long air duct 16 and air is supplied from the air holes 17 (see FIG. 4) of the troughs 12 and 13. Since it was made to blow off, supply air volume was not able to be adjusted for every part of a conveyor longitudinal direction. Therefore, the amount of blown air fluctuates in accordance with the fluctuation of the load on the belt 1 (the weight of the load), causing the following problems.
[0006]
That is, when the load is interrupted, the load applied to the belt becomes light when there is no load, so that a lot of air blows out and the belt flutters. On the other hand, since a lot of air blows out when there is no load, the amount of blown air is reduced and the levitation force is insufficient in the portion with other loads. As a result, there has been a problem that when the supply of the load changes, the belt cannot stably travel.
[0007]
In view of the above circumstances, an object of the present invention is to provide an air levitation belt conveyor that can stably run a belt even when a load fluctuation occurs on the belt.
[0008]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, an air levitation belt conveyor according to the present invention is provided with an air duct extending in the longitudinal direction of the conveyor on the lower surface of the carrier-side trough, and air holes communicating with the air duct are provided in the trough in the longitudinal direction of the conveyor. In the air levitation type belt conveyor, the air to the carrier side trough is blown out upwardly from the trough air hole, and thereby the levitation force is given to the belt moving on the trough. The duct is divided into a plurality of blocks in the longitudinal direction of the conveyor, and independent air supply pipes are connected to the air ducts of each block, and a flow control valve is provided in each air supply pipe to control the load on the belt passing through each block. The flow rate control valve is controlled in accordance with a signal from a means for detecting magnitude. That.
That is, the amount of air sent to each air duct of each block can be controlled according to the load fluctuation in each block on the belt, so that the belt can be stably driven.
[0009]
By providing a flow meter in the air supply pipe as means for detecting the magnitude of the load on the belt, the supply air volume for each block can be easily controlled to be constant.
[0010]
In addition, by adopting a system that controls the flow rate control valve corresponding to the downstream block according to the load detection signal on the belt when passing the upstream block in the transport direction, the actual belt A response earlier than the passage is possible, and a control delay can be avoided.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram of a belt conveyor according to an embodiment. In this belt conveyor, an air duct provided below the carrier-side trough 12 is divided into a plurality of blocks in the longitudinal direction of the conveyor, and the air ducts 16A, 16B, 16C, and 16D of each block are independent from the mother pipe 10, respectively. The extended air supply pipes 10A, 10B, 10C, and 10D are connected.
[0012]
Then, flow control valves 19A, 19B, 19C, 19D and flow meters (means for detecting the magnitude of the load on the belt) 20A, 20B, 20C, 20D are respectively connected to the air supply pipes 10A, 10B, 10C, 10D. When the detection values of the flow meters 20A, 20B, 20C, and 20D change according to the magnitude of the load on the belt 1 passing through each block, the flow control valves 19A, 19B, and 19C are corrected so as to correct the changes. , 19D is feedback-controlled.
[0013]
Since the return side air duct 16 does not need to be divided, it is the same as the conventional example. Further, with respect to the other configurations, the portions denoted by the same reference numerals are the same as in the conventional example. In FIG. 1, reference numeral 25 denotes a carry-in conveyor, and a cover 26 for preventing dust scattering is provided at the inlet to the air floating conveyor.
[0014]
In the air levitation belt conveyor configured as described above, when air is supplied from the blower 18 to each air duct 16 while the belt 1 is circulated, each trough 12 is provided from the air hole 17 of each air duct 16. , 13 is guided toward the both ends of the belt 1 in the width direction along the curved surfaces of the troughs 12, 13 through the troughs 12, 13 and the belt 1 traveling on the troughs 12, 13. , And discharged into the atmosphere from both ends in the width direction. As a result, an air layer is formed between the belt 1 and the troughs 12 and 13 that support the belt 1, and the belt 1 is brought into a non-contact state with respect to the troughs 12 and 13, and noise and vibration are generated. It will run smoothly.
[0015]
In this air levitation belt conveyor, when the load applied to the belt 1 of each block fluctuates due to fluctuations in the load supply, the supply air volume to the air ducts 16A, 16B, 16C, 16D, that is, the air supply pipes 10A, 10B, 10C, The amount of air flowing through 10D changes. When the airflow detected by the flow meters 20A, 20B, 20C, and 20D deviates from the set value, the flow control valves 19A, 19B, 19C, and 19D are feedback-controlled so as to correct the deviation, and the set airflow with respect to load fluctuations. Is preserved.
[0016]
For example, in a place where the load on the belt 1 is small, a large air volume tends to flow, but when the flow meter 20B detects this, the flow rate control valve 19B is controlled to the throttle side to keep the flow rate constant. In addition, the air volume tends to be small when the load is large, but when the flow meter 20C detects it, the flow control valve 19C is controlled to the open side to keep the flow rate constant.
[0017]
Therefore, the set air volume can be maintained with respect to any load fluctuation, the local increase in the air volume due to the variation in the load can be eliminated, and the occurrence of vibration and noise of the belt 1 can be prevented. Can do. Further, since the air volume in a place with a large load and a place with a small load can be appropriately controlled, the belt 1 can be stably driven, and an increase in driving load due to an increase in the contact ratio between the belt 1 and the trough 12 can be eliminated.
[0018]
It should be noted that the magnitude of the load on the belt 1 is best determined by the flow meters 20A, 20B, 20C, and 20D as in the above-described example for feedback control of the flow control valves 19A, 19B, 19C, and 19D. However, if it is a grade which determines the interruption of a load, a reflection type optical sensor can also be utilized, for example. In that case, the flow rate control valves 19A, 19B, 19C, 19D are throttled when there is no load, and the flow rate control valves 19A, 19B, 19C, 19D are controlled to open when there is a load. Try to keep it almost constant.
[0019]
Moreover, in the said embodiment, although the case where only the flow control valve 19A, 19B, 19C, 19D of the same block was controlled with the signal of flowmeter 20A, 20B, 20C, 20D provided for each block was shown, As shown in FIG. 2, delay control means 30 for controlling the air volume of the downstream block using control data of the upstream block may be provided. That is, since the belt 1 is traveling at a constant speed, for example, when a portion with a small load is detected on the upstream side, the portion reaches the downstream side after an elapse of an estimated time. Therefore, the control action on the upstream side (for example, the opening degree of the flow control valve) is reproduced by the downstream block by measuring when the small part of the load passes with a timer or the like, thereby performing the response operation for the actual load fluctuation. It can be done early. In particular, by performing such feedforward control, it is possible to improve the stability of control with respect to load fluctuations. As shown in FIG. 2, if a means (flow meter or the like) for detecting the magnitude of the load is provided only on the upstream side, the downstream detecting means can be omitted.
[0020]
【The invention's effect】
As described above, according to the present invention, the air duct on the carrier side is divided into a plurality of blocks in the longitudinal direction of the conveyor, and independent air supply pipes are connected to the air ducts of the respective blocks. A flow control valve is provided, and the flow control valve is controlled according to the signal from the means for detecting the load on the belt passing through each block. Can be controlled. Therefore, an increase in the amount of air supplied to the no-load portion can be prevented, and harmful phenomena such as belt vibration can be avoided. In addition, it is possible to avoid a decrease in the amount of air supplied to a portion having a load, and it is possible to prevent an increase in the contact ratio between the belt and the trough, thereby achieving stable running of the belt and an increase in driving load.
[0021]
In this case, by providing a flow meter in the air supply pipe as a means for detecting the load on the belt, even if there is a load fluctuation on the belt, the supply air volume for each block can be controlled to be constant. Stable driving can be realized.
[0022]
Also, by providing delay control means for feedforward control of the downstream side based on the upstream load detection signal, it is only necessary to reproduce the control content of the upstream block on the downstream side, so the magnitude of the load is detected. If only a minimum number of means are provided, temporary control can be performed. In addition, since the response can be made earlier than the actual belt passing, it is possible to avoid halving the effect due to control delay.
[Brief description of the drawings]
FIG. 1 is a side view showing a schematic configuration of an air levitation belt conveyor according to an embodiment of the present invention.
FIG. 2 is a side view showing a schematic configuration of an air levitation belt conveyor according to another embodiment of the present invention.
FIG. 3 is a side view showing a schematic configuration of a conventional air levitation belt conveyor.
FIG. 4 is a cross-sectional perspective view of a conventional air levitation belt conveyor.
[Explanation of symbols]
1 Belt 12 Carrier side troughs 16A, 16B, 16C, 16D Air duct 17 Air holes 10A, 10B, 10C, 10D Air supply pipes 19A, 19B, 19C, 19D Flow control valves 20A, 20B, 20C, 20D Means to detect the size of
30 Delay control means

Claims (2)

An air duct extending in the longitudinal direction of the conveyor is provided on the lower surface of the carrier-side trough, and air holes communicating with the air duct are arranged in the trough along the longitudinal direction of the conveyor. In the air levitation belt conveyor that squirts upward from the hole, thereby giving levitation force to the belt moving on the trough,
The air duct for the carrier-side trough is divided into a plurality of blocks in the longitudinal direction of the conveyor, and independent air supply pipes are connected to the air ducts of the respective blocks . A means for detecting the magnitude of the load on the belt passing through the block is provided in the block, and in accordance with a signal from the means for detecting the magnitude of the load on the belt passing through the block on the upstream side in the conveyance direction , An air-floating belt conveyor comprising delay control means for controlling the flow rate control valve corresponding to a block .   The air levitation belt conveyor according to claim 1, wherein a flow meter is provided in the air supply pipe as means for detecting the magnitude of the load on the belt.

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