JPH0551131A - Method of pneumatic transportation of granular body and device thereof - Google Patents

Abstract

PURPOSE:To ensure a required air amount sufficiently by blowing out the former auxiliary air having a certain high pressure in relation to the inner pressure of a tank in the upstream side of a transport pipe and the latter auxiliary air having the pressure higher than the inner pressure of the tank in the downstream side of the transport pipe. CONSTITUTION:In the former auxiliary air supply mechnism 15, the former auxiliary conduit 18 arranged in parallel with the transport pipe 2 is provided and the upstream side of the auxiliary conduit 18 is connected to an air supply source through a pressure reduction valve 23 and an open/close valve 22. In the latter auxiliary air supply mechanism 16, the latter auxiliary conduit 28 arranged in parallel with the transport pipe 2 is provided so as to be connected to the air supply source through the open/close valve 35 and a pressure adjusting valve. In the downstream side part in the transport pipe 2, the latter auxiliary air with a pressure value higher than the inner pressure of the tank is blown out from plural latter blow out port. Further, the auxiliary air is blown out by a blow out amount whose blow out amount per one blow out port is less than that of the former blow out port. The granular bodies whose density in the pipe is equalized can be transport to the end of the transport pipe stably without forming a plug by a small amount of auxiliary air in the downstream side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air transportation method and an air transportation apparatus for transporting powdery particles from a pressure tank through a transportation pipe to an appropriate container by pressure air, and in particular, an auxiliary air supply mechanism assists in the middle of the transportation pipe. The present invention relates to an air transportation method or an air transportation apparatus that supplies air to prevent adhesion, accumulation, or clogging of powder particles.

[0002]

2. Description of the Related Art In FIGS. 4 and 6 showing a conventional air transportation device, a pressure tank 1 in which powder particles are stored and pressure air for transportation is supplied, and a discharge portion 7 of the pressure tank 1 are connected. It is provided with a transportation pipe 2 that reaches the hopper 3 and an auxiliary air supply mechanism 50 that is connected in the middle of the transportation pipe 2. Then, pressure air is supplied from the tank pressurizing air supply pipe 8 into the pressure tank 1 to remove the powder or granules in the pressure tank 1.
The pressurized air is transported through the transportation pipe 2 to the hopper 3 at the end of the transportation pipe, and auxiliary air is supplied from a plurality of auxiliary air ejection nozzles 54 in the middle of the transportation pipe.

Each auxiliary air ejection nozzle 54 is provided in one auxiliary conduit 51 connected to an air supply source, and each auxiliary air ejection nozzle 54 is positioned at substantially equal intervals along the length of the transport pipe 2. As shown in FIG. 6, auxiliary air is jetted out.

In FIG. 5, the number of ejection nozzles 54 of the auxiliary conduit 51 is reduced, and one ejection nozzle 56 connected to another auxiliary conduit 57 is provided immediately after the outlet of the pressure tank 1 so that the auxiliary nozzle immediately after the tank outlet. The air is blown out intensively or intermittently.

[0005]

In the conventional structure of FIG. 4,
The injection amount of the auxiliary air supplied from the auxiliary conduit 51 is small on the upstream side of the transportation pipe 2 where the internal pressure is high, and tends to concentrate on the downstream side of the transportation pipe 2 where the internal pressure is low. Since air becomes deficient, the powder and granules may form a plug immediately after the tank 1 and may be clogged. On the other hand, when the cross-sectional area of the jet nozzle of the jet nozzle on the upstream side is made larger to increase the jet flow rate, the shortage of auxiliary air immediately after the tank 1 is resolved to some extent, but the total jet flow rate increases. , The flow velocity in the transport pipe at the transport end increases too much,
Crushing of powder and granules and abrasion of the transport pipe occur.

In the structure shown in FIG. 5, in addition to the auxiliary air by the auxiliary air supply mechanism 50, auxiliary air having substantially the same flow rate as that of the auxiliary air is intensively ejected immediately after the tank, thereby eliminating the shortage of auxiliary air immediately after the tank. However, the auxiliary air on the upstream side is concentrated at one location immediately after the tank outlet, and on the other hand, the amount of jetting from the portion of the transport pipe 2 from the upstream to the downstream is small. In the case of powder that is easy to form, there is a problem that when the discharge of the powder or granular material from the pressure tank 1 temporarily increases, clogging easily occurs.

[0007]

In order to solve the above-mentioned problems, the present invention is to supply pressurized air into a pressure tank so that the powder or granules in the pressure tank are passed through the transportation pipe by the above-mentioned pressure air to the end of the transportation pipe. In the air transportation method of the powder and granules, which supplies the auxiliary air into the transportation pipe from a plurality of locations along the transportation pipe while appropriately transporting it to the container, in the upstream portion of the transportation pipe, a constant pressure higher than the tank internal pressure is always applied. Front stage auxiliary air,
A plurality of front-stage jets are arranged in the length direction of the transport pipe at regular intervals or at appropriate intervals to inject the gas into the transport pipe. Air is arranged at substantially constant intervals or at appropriate intervals in the length direction of the transport pipe, and air is ejected from a plurality of post-stage ejection ports that are larger than the number of the pre-stage ejection ports, and further than the front-stage ejection ports. Auxiliary air is ejected with a small ejection amount per ejection port.

In order to carry out the above method, the present invention claims 2
The invention described is a pressure tank to which powdery particles are stored and to which compressed air for transportation is supplied, a transportation pipe connected to a discharge portion of the pressure tank to an appropriate container, and connected in the middle of the transportation pipe. In a powdery-particles air transportation device including an auxiliary air supply mechanism, an auxiliary air supply mechanism includes two types of upstream upstream auxiliary air supply mechanism and downstream downstream auxiliary air supply mechanism, Both auxiliary air supply mechanisms are equipped with jet outlets at a plurality of locations that are spaced apart in the length direction of the transport pipe, and the auxiliary air supply mechanism for the latter stage is different from the auxiliary air supply mechanism for the former stage in terms of the number of ejection ports. The number of jets per outlet is set to a small amount, and the pressure of the pre-stage auxiliary air supply mechanism is set to be always higher than the internal pressure of the pressure tank by a constant pressure. The pressure of the mechanism is more than the internal pressure of the pressure tank It is set to a high pressure value.

Further, in order to have a difference in flow rate per unit between the front-stage and rear-stage jets, the cross-sectional area of the rear-stage jets is made smaller than that of the front-stage jets, or As a filter to be attached to the ejection port, install a filter with a larger ventilation resistance (fine mesh) than the filter for the previous stage.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a piping diagram of an air transport device for powder or granular material to which the invention described in claim 2 of the present application is applied. In FIG. 1, the pressure tank 1 for storing the powder or granular material is a closed lid or the like. In addition to being configured to be hermetically sealed, a cone-shaped discharge part 7 made of sintered wire mesh is provided at the lower end, and the transport pipe 2 is connected to the lower end of the discharge part 7.

At the upper end of the pressure tank 1, a powder and granular material supply pipe 5 is provided.
Are connected via a valve 6, and the powder or granular material is supplied from the powder or granular material supply pipe 5 into the pressure tank 1. A pressure gauge 13 is provided at the upper end of the pressure tank 1, and the tank pressure P1 is measured by the pressure gauge 13.

At the lower part of the pressure tank 1, a fluidizing and tank pressurizing air supply pipe 8 is laterally connected to the cone-shaped discharge portion 7 via a valve 9, and the fluidizing air supply pipe 8 The powdery particles in the discharge part 7 are quickly discharged to the transportation pipe side by the pressurized air.

The transport pipe 2 is made of, for example, 1 inch stainless steel, and the length from the pressure tank discharge portion 7 to the downstream end is 50 m. A hopper 3 is disposed at the end of the transport pipe 2, and the transport pipe 2 has a rising portion 2a in the middle thereof in order to supply the granular material to the hopper 3 from above.
Extends above. Further, an opening / closing valve 10 is provided in a portion immediately after the outlet of the pressure tank 1. The upstream auxiliary air supply mechanism 15 is arranged on the upstream side of the transportation pipe 2, and the downstream auxiliary air supply mechanism 16 is arranged on the downstream side of the transportation pipe.

The pre-stage auxiliary air supply mechanism 15 includes the transport pipe 2.
And a pilot air type pressure reducing valve 2 on the upstream side of the pre-stage auxiliary conduit 18.
3 and the open / close valve 22 to connect to an air supply source. The pre-stage auxiliary conduit 18 has a pressure gauge 25 for the pre-stage auxiliary air.
Is provided, and at a substantially equal interval S1 in the length direction of the transport pipe.
A plurality of pre-stage ejection nozzles 19 are branched off from each other, and each pre-stage ejection nozzle 19 is connected in the middle of the transportation pipe 2 from immediately after the tank discharge portion of the transportation pipe 2 to the upstream side.

The pilot operating portion of the pilot air type pressure reducing valve 23 is connected to the inside of the pressure tank 1 via the pilot air pipe 14, and the pressure P2 of the auxiliary pipe 18 for the preceding stage is always constant with respect to the tank internal pressure P1. Control is performed so as to maintain a high value by Pt. That is, even if the tank internal pressure P1 fluctuates, the air pressure P2 in the pre-stage auxiliary conduit 18 remains P1 + P
controlled to be t.

The auxiliary air supply mechanism 16 for the rear stage includes the transport pipe 2
It is provided with a rear-stage auxiliary conduit 28 arranged in parallel with, and is connected to an air supply source via an opening / closing valve 35 and a pressure adjusting valve (not shown). In the auxiliary auxiliary conduit 28 for the latter stage, a plurality of ejection nozzles 2 for the latter stage are arranged at substantially equal intervals S2 in the length direction of the transport pipe.
9 are branched, and each of the post-stage ejection nozzles 29 is connected to the downstream side of the transport pipe 2 and reaches near the end of the transport pipe.

The space S2 between the rear jet nozzles 29 is larger than the space S1 between the front jet nozzles 19 (about 0.5 m), and is set to about 2 to 3 times (about 1 to 1.5 m). ing. The pressure in the rear auxiliary pipe 28 is set to a constant pressure value P3 higher than the tank internal pressure P1 by the pressure regulating valve. The pressure value P3 is set to be constant irrespective of the fluctuation of the tank internal pressure 1, and therefore is always higher than the maximum value of the tank internal pressure P1.

The front-stage jet nozzles 19 are arranged at several to several tens (for example, 10 spots), and the rear-stage jet nozzles 29 are several to several tens of times the number of the front-stage jet nozzles 19 (for example, 10). 45 places).

FIG. 2 shows the jet nozzles 1 for the front stage and the rear stage.
9 is an enlarged cross-sectional view of 9, 29, in which a downward socket portion 33 is formed on the lower surface of the transport pipe 2,
The ejection nozzles 19 and 29 having the ejection port 21 of the diameter D are screwed onto the inner peripheral female thread portion 33a. Jet nozzle 1
9 and 29 are taper screw portion 19a and straight screw portion 19
In addition to b, the taper screw portion 19a is integrally provided with a cylindrical portion 19c at the tip thereof.
Is screwed into the socket portion 33. The straight screw portion 19b is screwed into the front auxiliary pipe 18 or the rear auxiliary pipe 28, for example. Further, the cylindrical portion 19c has the ejection port 21 in the central portion. 38 is an O-ring.
Cylindrical portion 19 of front and rear jet nozzles 19 and 29
Filters 20 and 30 made of sintered wire mesh are fixed to the front end surface of c, and open inside the transport pipe 2 through the filters 20 and 30. In addition, the jet nozzle (filter) for the first stage 1
The diameter of 9 is about 2 to 3 times the diameter of the post-stage ejection nozzle 29.

As the powder or granules to be housed in the pressure tank 1 of FIG. 1, for example, powder or granules such as titanium oxide, zinc oxide or ferrite powder having a large adhesion and cohesiveness are stored.
The compressed air in the fluidized air supply pipe 8 is discharged into the transport pipe 2 from the discharge part 7 and transported in the transport pipe 2.

In the upstream portion of the transport pipe 2, pre-stage auxiliary air having a pressure P2 which is always larger than the tank internal pressure P1 by a constant pressure Pt is ejected for each pre-stage at a substantially constant interval S1 in the transport pipe length direction. It is ejected from the nozzle 19 into the transport pipe 2, respectively. That is, since the pressure P2 is set in association with a series of changes in the tank internal pressure due to the transportation of the granular material, the internal pressure of the transport pipe 2 and the internal pressure of the auxiliary conduit 18 are always a constant differential pressure and are always a constant amount. Auxiliary air is supplied.

Further, particularly in the case of the granular material having a large adherence / cohesiveness, the fluctuation of the discharge amount from the pressure tank 1 is large, and the pipe internal flow velocity is small on the upstream side because the pipe internal pressure is high.
Therefore, near a few meters from the tank outlet, the concentration fluctuation of the powder and granular material in the transport pipe is large and the tendency of adhesion, accumulation and blockage is particularly large, but it is necessary because a large amount of auxiliary air is injected upstream and dispersed. A sufficient amount of air is secured, the plug formation of the powder and granules is prevented, and the powder and granules are appropriately dispersed and flowed to the downstream side.

As described above, the granular material which is dispersed by the upstream auxiliary air on the upstream side and has a uniform concentration in the pipe has a constant pressure value P3 higher than the tank internal pressure P1 in the downstream portion in the transport pipe 2. Spacing position S1 of the preceding auxiliary air
The auxiliary air for the rear stage ejected from a large number of rear-stage ejection ports 29 at a wider interval S2 prevents the formation of plugs and is stably transported to the end of the transport pipe and supplied to the hopper 3. Even if the entire line is stopped due to a trouble, it can be easily restarted by the auxiliary air on the front and rear sides.

[0024]

[Another embodiment]

(1) In the embodiment shown in FIG. 1, the pre-stage ejection nozzle 19
And the set flow rate of the jet nozzle 29 for the latter stage is
Although the difference is created by making the cross-sectional area D of 31 different, the diameters D of both ejection ports are made the same, and the filters 20 and 30 having different ventilation resistances (for example, mesh density) are used. The size of the flow rate may be set by setting the flow rate. For example, a filter having a coarse passage resistance as the pre-stage filter 20 and having a characteristic of the graph A of FIG. 3 is used to secure a large flow rate, and a filter having a fine passage passage resistance as the post-stage filter 30 has a large passage resistance. , The flow rate is suppressed to be small by using the one having the characteristics of the graph B in FIG. In this way, the ejection nozzle itself can use common parts for the front and rear stages.

(2) Regarding the pressure adjustment in the auxiliary pipe 28 for the rear stage of FIG. 1, the internal pressure of the tank is used as the pilot pressure similarly to the auxiliary pipe 18 for the front stage so that the pressure is always higher than the internal pressure of the tank. Good. Regarding the pressure adjustment in the pre-stage auxiliary conduit 18, the tank internal pressure may be maintained at a constant value higher than the tank internal pressure instead of the pilot pressure.

(3) In the embodiment of FIG. 1, the space S1 between the front-stage ejection nozzles 19 and the space S2 between the rear-stage ejection nozzles 29 are constant, but in the front-stage auxiliary air supply mechanism 15, the tank is Immediately after the outlet, the spacing between the front-stage ejection nozzles 19 is made tight, and in the rear-stage auxiliary air supply mechanism 16, the spacing between the rear-stage ejection nozzles 29 on the transport pipe end side is made coarse, or one nozzle 29 is provided.
It is also possible to set the ejection amount from the nozzle to a smaller value. In addition to this, it is also possible to make a change such as making the intervals of the ejection nozzles 29 closer in the vicinity of the lower portion of the rising portion 2a.

(4) Further, in the first embodiment, the supply of the auxiliary air is divided into two stages, the front stage and the rear stage, but the present invention is not limited to this and can be divided into, for example, three.
In that case, the number of nozzles (density) and the ejection amount per nozzle in each section are set in three stages.

(5) In the first embodiment, the ejection amounts from the nozzles 19 and 29 are changed between the front stage side and the rear stage side.
It is possible to make the ejection amounts the same, to make the mounting pitch of the front stage side nozzles 19 dense, and to make the mounting pitch of the rear stage side nozzles 29 coarse.

(6) The jet nozzles 19 and 29 may be provided on the upper surface side of the pipe, or may be arbitrarily attached by providing them in a spiral shape with respect to the cross section of the pipe.

The auxiliary air for the front stage and the auxiliary air for the rear stage may be supplied individually or intermittently at the same time. Further, an inert gas other than air may be used.

[0031]

As described above, according to the present invention: (1) In the upstream portion of the transport pipe 2, the pre-stage auxiliary air having a jet pressure which is always a constant pressure larger than the tank internal pressure is supplied to the transport pipe. The plurality of front-stage ejection ports 21 arranged at substantially constant intervals or at appropriate intervals in the length direction are dispersed and ejected into the transport pipe 2, and the flow rate thereof is made larger than that in the downstream side portion. Therefore, a sufficient amount of air can be secured in the upstream side portion where the adhesion and accumulation tendency in the transport pipe 2 is large, and the formation of plugs of the granular material can be prevented. Especially when using a granular material such as titanium oxide, zinc oxide, or ferrite powder that easily adheres and accumulates, when discharged from the pressure tank 1, they are collectively discharged and discharged at one time (concentration). However, the tendency of adhesion and deposition becomes particularly large, but the effect of preventing plug formation is remarkable under such conditions.

(2) In the downstream portion of the transportation pipe 2, the auxiliary auxiliary air having a pressure value higher than the tank internal pressure is arranged at a substantially constant interval or at an appropriate interval in the length direction of the transportation pipe. More than the number of the front-stage ejection ports 21 is ejected from a plurality of rear-stage ejection ports 31, and the auxiliary air is ejected at a smaller ejection amount per ejection port than the front-stage ejection ports 21. Therefore, the powder or granules dispersed in the above-mentioned auxiliary air for the preceding stage and having a uniform concentration in the pipe are stably transported to the end of the transport pipe by a small amount of auxiliary air without forming a plug on the downstream side. be able to. In addition, by minimizing the amount of air and eliminating the excessive supply of auxiliary air on the downstream side, it is possible to eliminate unnecessary air consumption and reduce the flow velocity in the pipe to prevent problems such as crushing and abrasion of the pipe. You can

(3) As a whole, the auxiliary air is supplied to the upstream side and the downstream side of the transportation pipe in an amount and an air pressure suitable for each situation to supply the auxiliary air, so that the auxiliary air can be effectively and wastelessly supplied. By using it, powder particles such as titanium oxide having particularly large adhesion and cohesiveness can be stably pneumatically transported without being blocked.

[Brief description of drawings]

FIG. 1 is a piping diagram of an air transportation device according to the present invention.

FIG. 2 is an enlarged vertical cross-sectional view of front and rear jet outlet portions.

FIG. 3 is a graph showing a flow rate characteristic of a filter.

FIG. 4 is a piping diagram of a conventional example.

FIG. 5 is a piping diagram of another conventional example.

6 is an example (simplified view) of the conventional example of FIG.

[Explanation of symbols]

 1 Pressure Tank 2 Transport Pipe 3 Hopper (Container) 15 Pre-stage Auxiliary Air Supply Mechanism 16 Post-stage Auxiliary Air Supply Mechanism 19 Pre-stage Spout Nozzle 20 Pre-stage Filter 21 Pre-stage Spout Nozzle 29 Post-stage Spout Nozzle 30 Post-stage Filter 31 Post-stage Spout

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[Procedure amendment]

[Submission date] March 13, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0030

[Correction method] Change

[Correction content]

The auxiliary air for the front stage and the auxiliary air for the rear stage may be supplied individually or intermittently at the same time. Further, an inert gas other than air may be used. (7) FIG. 7 shows a modified example of the connection structure of the injection nozzles. For example, with respect to the post-stage injection nozzles 29, a plurality of them are collected in the collecting conduit 40 to form a block,
The collecting conduit 40 is connected to the rear auxiliary conduit 28. Such a block structure of the injection nozzle may be applied not only to the auxiliary air supply mechanism 16 for the rear stage of FIG. 1 but also to the auxiliary air supply mechanism 15 for the front stage as well as for the rear stage. It may be applied only to the auxiliary air supply mechanism 15. (8) FIG. 8 shows still another embodiment. As the pre-stage auxiliary air supply mechanism 15, the pre-stage auxiliary air conduit 18 is provided.
The main pipe portion 18a on the upstream side and the transport pipe 2 on the downstream side.
And a pressure accumulating pipe portion 18b arranged in parallel with each other, and the diameter of the pressure accumulating pipe portion 18b is adjusted so that it has a pressure accumulating action.
Thicker than. Similarly to the case of the front stage, the rear stage auxiliary air supply mechanism 16 also includes the rear stage auxiliary air conduit 2
8 is composed of an upstream side main pipe part 28a and a downstream side accumulator pipe part 28b arranged in parallel with the transport pipe 2, and the diameter of the accumulator pipe part 28b is adjusted so as to have a pressure accumulating action. Part 28
It is thicker than a. As a connection structure of each of the injection nozzles 19 and 29, a blocking structure similar to that of FIG. 7 is adopted. Further, in the transition portion D from the front-stage injection nozzle 19 to the rear-stage injection nozzle 29, both injection nozzles 19 and 29 are crossed so as not to interrupt the injection function,
They are arranged alternately. In the embodiment of FIG. 8, the accumulator pipe portions 18b and 28b are made thicker than the transport pipe 2,
Improves pressure accumulation. (9) In FIG. 8, front and rear injection nozzles 19, 2
Although both 9 have a block structure, only the rear stage side may have a block structure, and the front stage side may have a direct arrangement structure as shown in FIG. (10) In FIG. 8, the thickness of the pressure accumulating pipe portions 18b, 28b is made larger than that of the transport pipe 2, but the former pipe portions 18a, 2b
If it is thicker than 8a, it may be thinner than the transport pipe 29. (11) When the post-stage auxiliary air conduit 28 of FIG. 1 or the post-stage accumulator pipe portion 28b of FIG. 8 is thinner than the transport pipe 2, the block structure of FIG. 7 is adopted as the connection structure of the post-stage injection nozzle 29. Then, it is effective in preventing variations.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] Figure 7

[Correction method] Added

[Correction content]

FIG. 7 is a piping partial view showing a modified example of the injection nozzle.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] Figure 8

[Correction method] Added

[Correction content]

FIG. 8 is a piping diagram showing another embodiment of the present invention.

[Procedure amendment 4]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 7

[Correction method] Added

[Correction content]

[Figure 7]

[Procedure Amendment 5]

[Document name to be corrected] Drawing

[Correction target item name] Figure 8

[Correction method] Added

[Correction content]

[Figure 8]

Claims (4)

[Claims] 1. A pressure air is supplied into a pressure tank, and the powdery particles in the pressure tank are transported by the pressure air through a transportation pipe to an appropriate container at the end of the transportation pipe, and auxiliary from a plurality of locations in the middle of the transportation pipe. In the pneumatic transportation method of powder and granules for supplying air into the transportation pipe, in the upstream side portion of the transportation pipe, the pre-stage auxiliary air having a constant high pressure with respect to the tank internal pressure is constantly spaced at substantially constant intervals in the length direction of the transportation pipe. Alternatively, a plurality of pre-stage jets arranged at appropriate intervals are jetted into the transport pipe, respectively, and in the downstream side portion of the transport pipe, the post-stage auxiliary air having a pressure value higher than the tank internal pressure is transferred to the length of the transport pipe. Are arranged at substantially constant intervals or at appropriate intervals in the direction, and are ejected from a plurality of post-stage ejection ports that are larger than the number of the pre-stage ejection ports, and further from the front-stage ejection ports 1
A pneumatic transportation method of powdery or granular material, characterized in that auxiliary air is jetted with a small jetting amount per piece. 2. A pressure tank in which the powder and granules are housed and to which pressurized air for transportation is supplied, a transportation pipe connected to a discharge portion of the pressure tank and reaching a container as appropriate, and connected in the middle of the transportation pipe. In a powdery-particles air transportation device including an auxiliary air supply mechanism, an auxiliary air supply mechanism includes two types of upstream upstream auxiliary air supply mechanism and downstream downstream auxiliary air supply mechanism, Both auxiliary air supply mechanisms are equipped with jet outlets at a plurality of locations that are spaced apart in the length direction of the transport pipe, and the auxiliary air supply mechanism for the latter stage is different from the auxiliary air supply mechanism for the former stage in terms of the number of ejection ports. The number of jets per outlet is set to a small amount, and the pressure of the pre-stage auxiliary air supply mechanism is set to be always higher than the internal pressure of the pressure tank by a constant pressure. The mechanism pressure is higher than the pressure tank internal pressure An air transport device for powder particles, which is set to a high pressure value. 3. The powdery-particles pneumatic transportation device according to claim 2, wherein the cross-sectional area of the post-stage jet is smaller than the cross-sectional area of the pre-stage jet, and each post-jet jet of the post-stage jet is provided. An air transport device for powdery or granular material, characterized in that the ejection amount of is smaller than the ejection amount of the pre-stage ejection port. 4. The air-transporting device for powdery or granular material according to claim 2, wherein filters are provided at the front-stage ejection port and the rear-stage ejection port, respectively, and a filter having a larger ventilation resistance than the front-stage filter is used as the rear-stage filter. An air transportation device for powder particles, characterized by being provided.