JPH09278183A - Pulverulent body transporting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the pulverulent body transporting device which can prevent powder within a transporting pipe from being accumulated. SOLUTION: The pulverulent body transporting device is equipped with a transporting pipe 2, a plurality of gas blow-in nozzles N with each distance mutually separated in the longitudinal direction of the transporting pipe 2, a plurality of solenoid valves V interposed between each gas blow-in nozzle and a gas supply source 14, and with a valve selection circuit 12 controlling the solenoid valves V respectively. The valve selection circuit 12 is intermittently opened in accordance with a procedure in which each solenoid valve V is programmed, Each check valve for preventing gas from flowing out of the transporting pipe 2, is provided between each solenoid valve V and each gas blow-in nozzle N.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a powder transportation device provided with a transportation pipe for transporting powder with an air stream.

[0002]

2. Description of the Related Art As a powder transporting device of this type, a transport pipe connecting a powder supply source and a powder supply destination is provided, and the powder of the supply source is supplied together with air from an inlet of the transport pipe. 2. Description of the Related Art A powder transport device that continuously transports powder to the front has been conventionally used.

[0003]

However, in the conventional powder transport device, particles having a large specific gravity settle in the horizontally extending portion of the transport pipe and are deposited on the inner bottom surface of the transport pipe, or in the bent portion of the transport pipe. In some cases, there was a place where the air flow was stopped, and the phenomenon such as powder accumulation tended to occur, and the accumulated powder eventually caused blockage of the transport pipe, and maintenance such as cleaning of the blockage was often necessary.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a powder transporting device capable of preventing the accumulation of powder in a transport pipe.

[0005]

In order to solve the above-mentioned problems, a powder transport apparatus according to the present invention comprises a transport pipe for transporting powder and an inner surface of the transport pipe provided in the middle of the transport pipe. It is characterized by comprising one or two or more gas blowing nozzles which open to the above, and an on-off valve interposed between the gas blowing nozzle and the gas supply source. Powder transportation equipment.

A valve control mechanism for opening the on-off valve according to a certain control law may be further provided. Further, this valve control mechanism detects 1 or 2 of the pressure in the transportation pipe.
The above-mentioned pressure sensor may be provided, and the on-off valve may be controlled based on the output signals of these pressure sensors. Further, a release mechanism may be connected to the gas blowing nozzle so that the gas blowing nozzle communicates with the gas supply source when the internal pressure of the gas blowing nozzle changes more than the set pressure. Further, a check valve may be provided between the on-off valve and the gas blowing nozzle to prevent gas from flowing out from the inside of the transportation pipe.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION

[First Embodiment] FIG. 1 is a perspective view showing a first embodiment of a powder transport device according to the present invention. The apparatus of this embodiment transports the powder flowing down from the hopper 8 provided at the lower end of the powder container 1 containing the powder, together with the airflow through the transport pipe 2, and finally to the hopper 4.
The hopper 4 is of a cyclone separator type, and an exhaust pipe 6 is connected to the upper end of the hopper 4, and only the air is sucked by the decompression pump through the exhaust pipe 6. On the other hand, the powder is separated from the air and discharged from the lower end of the hopper 4 to the next step.

The upstream end of the transport pipe 2 is connected to a gas supply source 3 through a filter 5 for blocking the passage of powder, and a high pressure gas such as high pressure air is continuously or continuously supplied from the gas supply source 3. It is blown into the transport pipe 2 intermittently. At a position slightly downstream of the filter 5, a hopper 8 is provided on the upper surface of the transport pipe 2.
Is connected to the lower end of the powder, and the powder dropped from the hopper 8 into the transport pipe 2 is carried downstream by the high-pressure gas from the gas supply source 3.

The transport pipe 2 of this embodiment has a horizontal portion 2A extending horizontally from the upstream side, a vertical portion 2B extending upward from the horizontal portion 2A, and a horizontal portion 2C extending horizontally from the vertical portion 2B. And have. In the case of such a refraction shape, conventionally, powder was likely to be deposited on the bottom surfaces and the refraction portions in the horizontal portions 2A and 2C, and clogging was likely to occur. In order to solve this problem, in this embodiment, a large number of gas blowing nozzles N1 to Nm (collectively referred to as gas blowing nozzles N) are attached to the horizontal portions 2A and 2C of the transport pipe 2.

The gas blowing nozzles N are spaced apart from each other in the longitudinal direction of the transport pipe 2 and preferably open to the ceiling of the inner surface of the transport pipe 2, so that the gas is blown to the inner bottom surface of the transport pipe 2. It has become. It is preferable to open the ceiling of the inner surface of the transport pipe 2 because it has a stronger effect of blowing off the powder accumulated on the bottom surface, but the gas blowing nozzle N may be attached to another position if necessary. The mounting interval between the gas blowing nozzles N should be set in a preferable range according to the velocity of the gas flow ejected from the gas blowing nozzle N, the type of powder, and the like. To give a specific example, it is set to, for example, 200 to 300 mm so that the influence of the jet from the gas blowing nozzle N continues to the position of the next gas blowing nozzle N. However, it is not limited to this range. Also, the number of gas blowing nozzles N is not limited, and may be one in some cases.

The mounting angle α of the gas blowing nozzle N to the transport pipe 2 is not limited, but if the effect of accelerating the powder flow by the gas flow ejected from the gas blowing nozzle N is emphasized, 2, for example, 20 to 50
゜ is preferred. This is because setting the angle range in this way enhances the effect of blowing the powder collected on the inner bottom surface of the transport pipe 2 to the downstream side. On the other hand, if the powder has a large specific gravity and is likely to be deposited, it is preferable that the attachment angle α of the gas blowing nozzle N be close to a vertical angle to enhance the effect of blowing and stirring the powder deposited on the inner bottom surface of the transport pipe 2. . If necessary, α may be jetted toward the upstream side with an obtuse angle, or the mounting angles α of the individual gas blowing nozzles N may be different from each other.

One end of each independent supply pipe 9 is connected to each of the gas injection nozzles N via a check valve 16 (see FIG. 2) (only one is shown in FIG. 1). ). The check valve 16 allows the flow from the supply pipe 9 to the transport pipe 2, but blocks the outflow of the powder / gas from the transport pipe 2 to the supply pipe 9. The other end of each supply pipe 9 is connected to the outlet of an electromagnetic valve V provided in a controller (valve control mechanism) 10. The solenoid valves V are provided in the same number as the gas injection nozzles N (that is, V1 to Vm), and the inlets of the solenoid valves V are connected to a common gas supply source 14.

The solenoid valves V are controlled by the valve selection circuit 12. The valve selection circuit 12 of this embodiment controls the solenoid valves V one by one in order from the solenoid valve V1 on the upstream side to the solenoid valve Vm on the downstream side for a predetermined time. That is, when the solenoid valve V1 is opened and closed for a certain period of time, the solenoid valve V2 is opened at the same time or with an interval, and the solenoid valve V2 is opened for a certain period of time and at the same time or with an interval, the solenoid valve V2.
3 is opened for a certain period of time, and so on. In this way, after the last solenoid valve Vm is closed, immediately after that, or after a certain time elapses, the cycle is repeated from the beginning again. FIG. 3 is a graph showing an example of such control.

The time of one injection by the gas blowing nozzle N is not limited, but is, for example, 0.1 to 0.5.
It may be a pulse shape of seconds. It is preferable that the ejection velocity is considerably higher than the air velocity in the transport pipe 2. This is because the higher the ejection speed, the stronger the stirring action of the powder.
In general, it is considered preferable to increase the injection speed rather than to increase the injection time, because the pressure in the transport pipe 2 does not need to be increased so much and the powder stirring effect is high.

In this way, according to the control method of sequentially opening the solenoid valve V from the upstream side to the downstream side for a short time, the transport pipe 2
It is possible to blow out the powder flowing inside one after another toward the downstream, agitate the powder to enhance the fluidity again, and at the same time accelerate the transportation. In particular, when the powder blown off by the gas blowing nozzle N on the upstream side moves to the position of the next gas blowing nozzle N adjacent on the downstream side, the gas is blown out from the gas blowing nozzle N. If is selected, the most efficient powder transportation can be performed. From this point of view, it is presumed that when the powder having a large specific gravity is transported, the injection interval is lengthened, and when the powder having a small specific gravity is transported, the injection interval is preferably shortened.

Further, according to the above control method, since only one solenoid valve V is opened at a time, even if the ejection pressure from each gas blowing nozzle N is large, the gas supply source 14
The amount of gas supplied from the device may be relatively small, and has an advantage that the operating cost is not increased.

According to the powder transport device having the above-mentioned structure,
A plurality of gas blowing nozzles N ejects a gas flow into the transport pipe 2 in a pulsed manner, and powder that tends to stay on the bottom surface of the transport pipe 2 can be blown off and flowed. It is possible to effectively prevent the transport pipe 2 from being clogged due to the accumulation of the powder, because the powder is not deposited even on the 2C and the bent portion.

Further, since the powder can be transported while being stirred with a gas while maintaining a good flow state, the gas supply source 3
Even if the flow rate of the transport gas supplied from the product is the same as before, it is possible to increase the powder transport speed, and it is possible to transport a larger amount of powder than before. Is eliminated and stable transportation is possible.

Further, since the density of the powder in the transport pipe 2 can be reduced, it is possible to reduce the impact of the powder lump flowing in the straight portion of the transport pipe 2 colliding with the bent portion of the transport pipe 2 and exerting an impact. The wear and damage of the transport pipe 2 due to impact can be reduced, and the life of the transport pipe 2 can be extended. In addition, in this embodiment, since the switching of the solenoid valve V is automatically controlled by the valve selection circuit 12, it is possible to switch the injection at high speed with good timing, a high stirring effect can be obtained with a small gas injection amount, and the transportation can be performed. Not only can pressure fluctuations in the pipe be minimized, but labor can be saved. Further, this device has the advantage that there are few mechanical moving parts, the introduction cost and the maintenance cost are low, and the start-up is quick, so that the initial time loss is small even in the case of intermittent transportation.

Although the gas injection nozzle N is attached only to the upper portion of the transport pipe 2 in the above-described embodiment, the present invention is not limited to this structure and may be attached to any position of the transport pipe 2. For example, as shown in FIG. 4, it is possible to arrange the gas blowing nozzles N on the outer circumference of the transport pipe 2 in a spiral arrangement. Other configurations may be similar to those of the above embodiment.

Further, in the above embodiment, the supply pipe 9 and the solenoid valve V which are independent for each gas blowing nozzle N are provided, but a plurality of gas blowing nozzles N are commonly used for the supply pipe 9 and the solenoid valve V. It is also possible to connect to. Further, the control method by the valve selection circuit 12 may be changed so that the gas is ejected from a plurality of gas injection nozzles N at a time. Further, a gas other than air, for example, an inert gas such as nitrogen gas may be supplied from the gas supply source 3 and the gas supply source 14. Further, in the above embodiment, the solenoid valve V is controlled by the valve selection circuit 12, but it may be possible to manually open and close each on-off valve in some cases.

[Second Embodiment] FIG. 5 shows a main part of a second embodiment of the powder transport device according to the present invention. In this embodiment, the pressure sensors S1, S2 ... For detecting the pressure inside the transport pipe 2 are installed at one location of the transport tube 2 or at a plurality of locations spaced apart in the longitudinal direction of the transport tube 2. It has a feature. The configuration not shown is the first
This is the same as the embodiment.

Each of the pressure sensors S1, S2 ... Is connected to the above-mentioned valve selection circuit 12, and the valve selection circuit 1
When any of the pressure sensors S1, S2 ... Detects a pressure change (rise or fall) above a certain level, 2 is a solenoid valve V corresponding to the gas blowing nozzle N located closer to the upstream side of the pressure sensor. Is opened, and the solenoid valve V is controlled so as to blow out the gas from the gas blowing nozzle N. For example, in the illustrated example, when the pressure sensor S1 detects a pressure change, the solenoid valves V1 and V2 are opened and the gas injection nozzle N is opened.
When the gas is blown in pulses from 1, 1 and N2 and the pressure sensor S2 detects a pressure change, the solenoid valves V3 and V4 are opened and the gas is blown in pulses from the gas blowing nozzles N3 and N4.

To determine the pressure change, the normal pressure value at the sensor position is stored in the valve selection circuit 12, the normal value is compared with the pressure value detected by the pressure sensor S, and the detected pressure value is detected. If is higher or lower, it can be determined as a pressure change. When the specific pressure sensor S detects a pressure change, it is considered that the transport pipe 2 is blocked in the vicinity of the upstream side of the pressure sensor S. Therefore, according to the embodiment having such a configuration, the transport pipe 2 After the blockage occurs, it is possible to quickly and intensively blow the gas into the blocked part, whereby the blockage of the transport pipe 2 can be effectively avoided.

The gas blowing nozzle N may blow the gas only when the pressure sensor S detects a partial blockage of the transport pipe 2, or except when a partial blockage occurs. However, as in the first embodiment, the gas may be continuously blown from the gas blowing nozzle N in order. Further, the pressure sensor S may be installed at intervals of one gas injection nozzle N or at intervals of three or more. Further, only when one of the pressure sensors S detects the blockage, all the solenoid valves V are set to the first position.
It is also possible to adopt a configuration in which opening and closing are performed in order as in the embodiment. Further, when the pressure sensor S detects a pressure drop, an alarm may be issued and an operator may manually open the on-off valve.

[Third Embodiment] FIG. 6 shows a main part of a third embodiment of the powder transport apparatus according to the present invention. In this embodiment, the release valve 26 is provided in the middle of each supply pipe 9.
Is interposed. These release valves 26
Is for automatically connecting the inside of the supply pipe 9 to a gas supply source (not shown) when the pressure inside the supply pipe 9 changes. Other configurations not shown may be the same as those in the first embodiment. That is, the valve selection circuit 12 opens each solenoid valve V in the programmed order and ejects gas from the corresponding gas injection nozzles N, N2 ...

In this embodiment, when the pressure inside the gas blowing nozzle N changes due to blockage occurring immediately below the ejection port of any of the gas blowing nozzles N1, N2 ,.
The corresponding release valve 26 opens and gas is blown into the transport pipe 2 from the gas blowing nozzle N in which the blockage has occurred. Due to this blowing, the powder causing the blockage is blown away, so that the effect of removing the blockage is obtained.

Further, by providing the release valve 26, even when the inside of the transport pipe 2 is blocked and cannot be removed,
Since the pressure in the transport pipe 2 does not drop extremely, there is an advantage that there is no fear of abnormal operation when the device is stopped due to the pressure drop of the transport pipe 2 or excessive load on the decompression pump.

[0029]

As described above, according to the powder transport apparatus of the present invention, the gas is injected into the transport pipe by the gas blowing nozzle, and the powder that tends to stay on the bottom surface of the transport pipe is blown off and flowed. Therefore, the powder is not deposited even on the horizontal portion or the bent portion of the transport pipe, and it is possible to effectively prevent the transport pipe from being blocked due to the powder deposition.

Further, since the powder can be transported while being stirred with the gas while maintaining a good flow state, even if the flow velocity of the transport gas supplied from the gas supply source is the same as the conventional one,
The powder transportation speed can be increased, a larger amount of powder can be transported than before, and stable transportation can be performed.

Further, since the density of the powder in the transport pipe can be reduced, it is possible to reduce the impact of the powder lump flowing in the straight portion of the transport pipe on the bent portion of the transport pipe, and such impact. It is possible to extend the service life of the transport pipe by reducing the wear and damage of the transport pipe due to.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a powder transport device according to the present invention.

FIG. 2 is a vertical cross-sectional view showing a mounted state of a gas blowing nozzle of the powder transport device.

FIG. 3 is a graph showing an operation of a valve selection circuit of the powder transport device.

FIG. 4 is a cross-sectional view showing a modified example of the first embodiment of the powder transport device according to the present invention.

FIG. 5 is a side view showing a main part of a second embodiment of the powder transport device according to the present invention.

FIG. 6 is a side view showing a main part of a third embodiment of the powder transport device according to the present invention.

[Explanation of symbols]

 1 powder container 2 transport pipe 2A, 2C horizontal part 2B vertical part 3 gas supply source 4 hopper 6 discharge pipe 8 hopper N1, N2 ... gas injection nozzle V1, V2 ... solenoid valve (open / close valve) 10 controller 12 valve selection circuit 14 gas Supply source 16 Check valve S1, S2 ... Pressure sensor 26 Release valve

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshihiko Okamura 622, Funaishikawa, Tokai-mura, Naka-gun, Ibaraki Prefecture Mitsubishi Nuclear Fuel Co., Ltd. Tokai Works

Claims (5)

[Claims] 1. A transport pipe for transporting powder, one or more gas blowing nozzles provided in the middle of the transport pipe and opening to an inner surface of the transport pipe, the gas blowing nozzle and a gas supply source. And a shutoff valve interposed between the powder transport device and the on-off valve. 2. A valve control mechanism for opening the on-off valve according to a constant control law.
The powder transport device described. 3. The valve control mechanism has one or more pressure sensors for detecting the pressure in the transportation pipe, and controls the on-off valve based on output signals of these pressure sensors. The powder transport device according to claim 2. 4. A release mechanism is connected to the gas blowing nozzle so as to communicate the gas blowing nozzle with a gas supply source when the internal pressure of the gas blowing nozzle changes more than a set pressure. The powder transport device according to claim 1. 5. A check valve for preventing gas from flowing out from the inside of the transportation pipe is provided between the on-off valve and the gas blowing nozzle. The powder transport device described.