JPS6218447B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a transport device for transporting powder or granular material from a pressure tank to a destination using a transport gas.

In conventional pressure tank type pneumatic transport equipment,
When the amount and pressure of the transport gas supplied into the tank fluctuates, the amount of powder and granules discharged from the tank into the transport pipe changes significantly, and as a result, the amount of powder and granules per unit time changes. There is a problem in that the amount of emissions (transported amount) cannot be maintained constant or set arbitrarily. Furthermore, the discharge amount is easily influenced by the physical properties of the powder and granules, and the discharge amount fluctuates significantly due to flushing (rapid fluidization of the powder and granules), and in this respect as well, it is difficult to control the discharge amount. Moreover, if you perform a stop operation in the middle of discharging,
There is a problem in that the actual ejecting operation cannot be stopped immediately, resulting in dripping, leakage, etc.

In other words, in conventional gas transport devices, the entrance of the transport passage is opened directly at the bottom of the powder storage space in the tank, and the powder and granules in the tank are transported to the entrance of the transport passage using only gravity and the transport gas flow. Since the amount of powder and granular material flowing into the transport passage is significantly affected by the pressure of the transport gas and the flushing of the granular material, it is difficult to adjust the discharge amount (transport amount). There's a problem.

In order to solve the above problem, the present invention connects a powder input passage having a valve and a transport gas supply passage to the upper space of a powder tank, and provides a guide cylinder extending vertically in the tank. The outlet at the upper end of the guide tube is opened into the upper space, and a space is formed below the outlet at the upper end of the guide tube to collect the powder and granular material, and the powder and granule are collected from the inlet at the lower end of the guide tube to the outlet at the upper end. A screw feeder to be transported is installed in a guide tube, a powder discharge port is provided in the middle of the guide tube, a powder discharge passage extending outside the tank is connected to the discharge port, and a powder discharge passage extending outside the tank is connected to the outlet from the upper end of the guide tube. The present invention is characterized in that the portion up to the powder discharge port forms a transportation air passage that connects the upper space and the powder discharge passage, and the drive shaft of the screw feeder is connected to a drive device.

Next, embodiments will be described with reference to the drawings.

In FIG. 1, which is a schematic vertical cross-sectional view, a powder input passage 2 and a transport gas supply passage 3 are connected to the upper end of a pressure tank 1, and valves 4 and 5 are provided in the middle of each passage 2 and 3, respectively. It is provided. The upper end of the passage 2 is connected to the hopper 9, and the unillustrated end of the passage 3 is connected to a transport gas supply source. tank 1
A vertically extending guide cylinder 10 is supported at the center of the cylinder via a bracket (not shown). The inlet 11 at the lower end of the guide tube 10 is separated from the tank bottom wall 12 by a gap, and in the embodiment shown in FIG. It is tapered. An outlet 14 at the upper end of the guide cylinder 10 opens into an upper space 15 of the tank 1, and a baffle 24 is provided near the upper part of the outlet 14. A screw feeder 16 is disposed within the guide tube 10 over its entire length. Drive shaft 17 of screw feeder 16
protrudes downward through the bottom wall 12, and its lower end is connected to a variable speed motor 21 via a pair of bevel gears 19 and a reduction gear 20. A stirring blade 22 is attached to the drive shaft 17 between the inlet 11 and the bottom wall 12. 23 is a shaft seal provided at a portion where the drive shaft 17 passes through the bottom wall 12. The guide cylinder 10 has a discharge port 25 near its upper end, and a powder discharge passage 26 extending outside the tank 1 is connected to the discharge port 25 . A portion of the passage 26 connected to the outlet 25 extends downward from the outlet 25 and forms a droplet 29. The passage 26 is provided with a discharge valve 27 at a portion protruding from the tank 1. 30 is powder 31
This level switch is attached to the side wall of the tank 1, and the vertical position of the switch 30 is such that the top surface 32 of the powder 31 is slightly below the outlet 14 of the guide tube 10 as shown in FIG. It is determined that the upper surface 32 is detected when it reaches the point. A pressure switch 33 detects the pressure in the upper space 15 of the tank 1, and is attached to the upper part of the tank 1.

The effect will be explained. When charging powder into an empty tank 1, the transport gas valve 5 and discharge valve 27 are closed, and when the receiving valve 4 is opened, the powder in the hopper 9 passes through the charging passage 2 into the tank 1. fall to In this case, since the baffle 24 is provided above the guide tube outlet 14, the powder particles will not fall into the guide tube 10. When the upper surface 32 of the granular material 31 reaches the illustrated position, the level switch 30 detects this and issues a signal such as an electric signal or a buzzer, and the receiving valve 4 is automatically or manually closed by that signal. Upon completion of the charging operation, the tank 1 is sealed.

Next, when the transport gas valve 5 is opened, the transport gas is supplied from the gas supply passage 3 into the tank 1, and the inside of the tank 1 is pressurized. When the pressure switch 33 detects that the tank internal pressure has reached a predetermined value, the valve 5 is closed and the tank waits for the start of transportation.

When a command to start transport is received from outside, the prime mover 2
1 to operate the screw feeder 16 and stirring blade 22. Then, the screw feeder 16 conveys the powder 31 from the inlet 11 of the guide tube 10 to the outlet 14, and part of the powder that reaches the discharge port 25 falls into the drop port 29, and the remaining The portion falls from the outlet 14 onto the top surface 32 of the granular material. Further, the stirring blades 22 prevent the formation of bridges near the inlet 11 and also introduce the powder and granular material 31 into the inlet 11. Therefore, even if the granular material 31 has strong brittleness, it can be reliably transported by the feeder 16.

Next, when the discharge valve 27 and the transport gas valve 5 are opened, the high pressure transport gas flows from the upper space 15 to the guide tube outlet 14,
The powder and granules that flow into the discharge pipe 26 through the discharge port 25 and are sent to the drop port 29 by the feeder 16 are sequentially entrained in the gas flow and transported within the discharge pipe 26 to the destination. Immediately after opening the discharge valve 27,
An uncontrollable gas flow (high-speed and turbulent gas flow) occurs in the outlet 25 and the outlet pipe 26, but even in that case, only the powder in the outlet 29 is discharged, so an extremely large amount of gas is generated. The powder and granules are not discharged instantaneously, and the discharge pipe 26 is not clogged.
In normal operation after the discharge valve 27 is opened, the amount of powder and granules discharged per unit time matches the amount of powder and granules sent to the drop port 29 by the feeder 16, and the amount of powder sent to the drop port 29 is As long as the amount of particles is within the limit (within the occlusion area) of the amount entrained by the transport gas (solid-gas mixture ratio), the amount of emissions will not change even if the amount or pressure of the transport gas changes. Therefore, if the number of revolutions of the prime mover 21 is changed to increase or decrease the conveyance amount of the feeder 16, the amount of powder and granular material discharged will also change in exact response, and while the number of revolutions of the prime mover 21 is kept constant, The amount of powder discharged is also kept constant. In this way, the discharge amount corresponds to the feeder conveyance amount and is not affected by the transport gas, so that even if flashing occurs in the powder or granular material 31, the discharge amount is kept constant.

To change the emission amount, change the rotation speed of the prime mover 21,
This can be done easily and accurately by changing the feeder conveyance amount.

If you want to stop the discharge operation midway, the prime mover 2
1 to stop conveyance by the feeder 16, and at the same time close the valves 5 and 27. Then the trap 29
Since the powder and granules are no longer sent to the discharge pipe 26, even if the discharge valve 27 is not fully closed or the closing timing is delayed, the powder and granules will not be transported through the discharge pipe 26. No dripping or leakage from the powder or granules occurs.

As explained above, according to the present invention, the amount of powder discharged per unit time corresponds to the conveyance amount of the screw feeder 16. ), the discharge amount per unit time can be kept constant, and by controlling the conveyance amount of the feeder 16 by changing the rotation speed of the drive shaft 17, the amount of powder discharged (transportation amount) can be set accurately to any value. Furthermore, even if the operation is stopped during discharge, no dripping or gap leakage will occur. Note that the prime mover 21 does not necessarily have to be of a variable speed type.
The number of rotations may always be constant. Even in that case, by replacing the prime mover 21 and reducer 20 with those of different specifications, the rotation speed of the drive shaft 17 can be freely changed, and the discharge amount can be set to an arbitrary value.

The present invention can also be embodied as shown in FIG. In FIG. 2, the guide cylinder 10 and the screw feeder 16 are located at a position shifted to the right in the figure with respect to the input passage 2 at the upper center of the tank 1, and the lower part of the tank side wall 13 has a smaller diameter as it goes to the lower right in the figure. It has a deformed tapered shape. A drive shaft 17 of the feeder 16 projects upward and is connected to the prime mover 21 at its upper end. The baffle 24 of FIG. 1 has been eliminated in the embodiment of FIG.

In addition, when embodying the present invention, the discharge port 2 in FIG.
5 can also be provided at an intermediate portion of the guide tube 10 in the vertical direction. However, in the area between the outlet 25 and the outlet 14, surplus powder is transported upward, so the area between the outlet 25 and the outlet 14 is
5 is disposed downward, it becomes difficult for the transport gas to flow into the exhaust port 25, which is not preferable. Again, dropout 29
can also be made horizontal.

[Brief explanation of the drawing]

1 and 2 are schematic vertical cross-sectional views of different embodiments, respectively. DESCRIPTION OF SYMBOLS 1... Tank, 2... Powder input passage, 3... Transport gas supply passage, 4... Valve, 10... Guide tube, 11... Inlet, 14... Outlet, 15... Upper space,
16... Screw feeder, 17... Drive shaft, 21
...Prime mover (drive device), 25...Discharge port, 26...Powder and granular material discharge passage, 31...Powder and granular material.

Claims (1)

[Claims] 1. A powder input passage with a valve and a transport gas supply passage are connected to the upper space of the powder tank, a guide cylinder extending vertically is provided in the tank, and an outlet at the upper end of the guide cylinder is opened to the upper space. A space is formed below the outlet at the upper end of the guide cylinder to collect the powder and granules, and a screw feeder is installed inside the guide cylinder to convey the powder from the inlet at the lower end of the guide cylinder to the outlet at the upper end. A powder discharge port is provided in the middle of the guide tube, and a powder discharge passage extending outside the tank is connected to the discharge port.
A portion of the inside of the guide cylinder from the upper end outlet to the powder discharge port forms a transportation air passage connecting the upper space and the powder discharge passage, and connects the drive shaft of the screw feeder to the drive device. Features: Powder transportation device.