JP2013147321A - Material pneumatic conveying system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem with a conventional system of pneumatically transporting powder and granular materials, wherein there has been no material pneumatic transport system capable of safely handling even an inflammable one in terms of material properties, and capable of achieving good balance between a purge gas pressure and a pneumatic supply pressure therefor without particularly requiring the setting of a length or a diameter of piping.SOLUTION: A system includes a hopper, a feeder conveying a material from the hopper, and a chute dropping and discharging the material from the feeder, wherein a distal lower end of the chute is connected to a venturi and wherein the material is discharged from the venturi by pneumatic transport. Even a very small amount of the material may be sent by a very fine tube by sucking and discharging air in the hopper, the feeder, and the chute from a supply/suction pipe provided at the hopper, and by then filling purge gas for replacement to perform the purging.

Description

  The present invention relates to a pneumatic transportation system for materials, and more particularly to a pneumatic transportation system for materials in which a fine granular material is stably blown even in a very small amount by air and sprayed onto an object from a fine tube.

  In order to forcibly convey the fine granular material, it is necessary to apply a positive or negative pressure to the air or gas serving as a medium on which the material is placed. Although it is possible to obtain this pressure only with the purge pressure that eliminates the gas adsorbed in the pipe serving as the carrying path, in this case, a large restriction is imposed on the diameter and length of the pipe, the amount of material, and the pressure value. It will be.

  Therefore, in general, a venturi is used for such pneumatic transportation, and a discharge port is provided on the secondary side of the venturi. As a system provided with this venturi, a system having the configuration shown in FIG. 2 is conceivable. In FIG. 2, reference numeral 1 denotes a hopper for supplying a fine powder material P. The hopper 1 has an opening, and a feeder 2 for conveying the material P by a fixed amount is provided on the lower side thereof, and a chute 3 for dropping and discharging the material P downward is provided on the feeder 2. Yes.

  On the other hand, 4 in the figure indicates a venturi, 5 is a receiving hopper of material P formed on the upper side of the venturi 4, and the material is dropped and supplied from the chute 3 to the receiving hopper 5. It is to be pumped by suction and air pressure. However, in this configuration, the material P is scattered around by reverse injection or the like.

  Further, in the case shown in FIG. 3, the venturi 4 is configured to assist intake air, and an auxiliary pipe 6 is provided around the chute 3, and the auxiliary pipe 6 and the receiving hopper 5 are connected by a connecting pipe 7. 3 and the venturi 4 have a sealed structure, and an auxiliary pressure is applied to the feeder 2 and the chute 3 portion so that the intake pressure of the venturi 4 is not released by the above-described sealed structure, and the air pressure is sent. However, in this configuration, realization is difficult due to the characteristics of the material, and it becomes necessary to set the length and diameter of the transport pipe. Also in this case, the hopper 1 has an opening.

  Further, in the case shown in FIG. 4, the hopper 1 is also covered and sealed, and the transportation of the hopper 1, feeder 2 and chute 3 is replaced with a replacement gas (for example, nitrogen gas), and the air is transported by the venturi 4. It is the structure to do. However, in this case, the replacement with the replacement gas cannot be performed completely, and it becomes difficult to maintain the balance between the purge pressure and the idle pressure for conveying the material.

  Although the applicant investigated the prior technical literature regarding the invention of the present application, it was not possible to find a literature that was particularly related to the present application and considered similar.

  The problem to be solved by the present invention is that, in the past, when pneumatically conveying a granular material, even if it is flammable due to the characteristics of the material, it can be handled safely, and the replacement gas pressure There is no pneumatic transport system for materials that can achieve a good balance between the air pressure and the air pressure, and does not need to set the length or diameter of the pipe.

  In order to solve the above-described problems, a pneumatic transportation system for a material according to the present invention includes a hopper, a feeder that conveys the material from the hopper, and a chute that drops and discharges the material from the feeder. Is a system that connects to the venturi and releases the material from the venturi by pneumatic transportation. After the air in the hopper, feeder and chute is sucked and discharged from the intake and intake pipes provided in the hopper, the replacement gas is replaced and filled. By purging and purging, it is possible to feed even a very small amount of material or an extremely thin tube.

  Further, in the pneumatic transportation system for materials according to the present invention, the supply path for the replacement gas is branched and connected to the chute, feeder and hopper, and is branched on the primary side of the purge pressure adjuster. The chute is also connected to the venturi, and the chute has a double-pipe structure.

  Furthermore, the pneumatic transport system for materials according to the present invention is characterized in that the replacement of the air and the replacement gas is performed at the same pressure, and the material discharged from the venturi is transported as a mixed gas with the replacement gas. The above-described replacement gas is an inert gas.

  The pneumatic transportation system for materials according to the present invention is configured as described above. Therefore, the chute internal pressure and the venturi suction pressure are substantially the same, the material air feeding pressure and the purge pressure are well balanced, accurate air transportation is realized, and finally the material is sprayed onto the object In addition, since the chute part has a double tube structure, it can cope with turbulent flow. The material of the granular material conveyed and supplied in a minute amount (a few g per hour is acceptable) can be stably pneumatically transported even in an ultra-thin tube having an inner diameter of 2 mm, for example.

It is a block diagram which shows the pneumatic transportation system of the material which implemented this invention. It is a figure which shows a 1st reference example. It is a figure which shows the 2nd reference example. It is a figure which shows the 3rd reference example.

  This was realized by configuring as illustrated in the drawings and described in the examples.

  Next, an example of a preferred embodiment of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the part which is common in the reference example mentioned above, and detailed description is abbreviate | omitted. In this embodiment, the hopper 1 charged with the material P is covered and sealed, and a vacuum pump is connected to a part of the lid 8 via a cock 9.

  By opening the cock 9 and operating the vacuum pump, the air in the conveying system for the material P of the hopper 1, the feeder 2 and the chute 3 is sucked out as much as possible, and the vacuum state is reduced to the atmospheric pressure or lower. Further, a hopper purge pipe 10 for replacing and sending the replacement gas is connected to a part of the lid 8 described above.

  The above-described replacement gas (inert gas, for example, nitrogen gas) is sealed in a cylinder (gas source), and is supplied by being pumped from the cylinder through the pipeline 11. The pipe 11 is provided with a valve 12 at the base end for adjusting the original pressure of the replacement gas, and is provided with a cock plug 13 through which the replacement gas passes on the secondary side.

  Further, a branch pipe 14 is provided on the secondary side of the cock stopper 13 to branch the replacement gas into a material transport system and a transport system having the venturi 4. A valve 15 for adjusting the purge pressure is provided in the pipe line 11 toward the transport system, and the hopper purge pipe 10 is branched on the secondary side. On the secondary side, a feed purge pipe 16 for sending replacement gas to the feeder 2 is connected to a portion directly above the chute 3. The pipe line 11 is linearly connected to a part of the auxiliary pipe 6 to form a chute purge pipe 17.

  On the other hand, the second pipe line 11a branched by the branch pipe 14 and having the venturi 4 serves as an air transport system for the material P, and is provided with a valve 18 for adjusting the air feed pressure. On the secondary side of the valve 18, a cock plug 19 for opening and closing the air feeding pressure is provided, and the cock plug 19 is connected to the rear end side of the venturi 4.

  On the secondary side of the venturi 4, there is provided a cock stopper 20 for pneumatically transporting the material P. By opening the cock stopper 20, the mixed gas containing the material P is jetted from the tip (nozzle), and the object Will be sprayed. It should be noted that the pipe on the secondary side of the cock plug 20 can be an extremely thin tube having an inner diameter of 2 mm.

  The replacement with the replacement gas described above is performed after the air in the transport system is sucked out and discharged as much as possible, and substantially complete replacement can be realized. This purge pressure can also be adjusted after the determination of the air feeding pressure in the transport system, so it is very well balanced. In the figure, reference numeral 21 denotes an internal pressure monitor. Regardless of the presence of the internal pressure monitor 21, depending on the strength of the air feeding pressure and the purge pressure, a structure that allows visual observation can be used. Further, since the chute 3 has a double tube structure, it can cope with turbulent flow and does not scatter material around.

  The pneumatic transportation system for materials according to the present embodiment is configured as described above. In this embodiment, the purge of the replacement gas is performed using the respective pipes for the hopper, the feeder, and the chute. However, for example, the purge pipe 16 for the feeder 2 can be omitted. In addition, although an inert gas such as nitrogen gas is assumed as the replacement gas, it is needless to say that air can be used as the replacement gas regardless of this.

DESCRIPTION OF SYMBOLS 1 Hopper 2 Feeder 3 Chute 4 Venturi 5 Receiving hopper 6 Auxiliary pipe 7 Connection pipe 8 Lid body 9 Cock stopper 10 Hopper purge pipe 11 Pipe line 11a Second pipe 12 Valve 13 Cock stopper 14 Branch pipe 15 Valve 16 Feed purge pipe 17 Chute purge pipe 18 Valve 19 Cock stopper 20 Cock stopper 21 Internal pressure monitor P Material

Claims (6)

  A hopper and a feeder that conveys material from the hopper, and a chute that drops and discharges the material from the feeder, the chute is connected to the venturi and discharges the material by pneumatic transportation from the venturi, After sucking and discharging the air in the hopper, feeder and chute from the air intake / intake pipe provided in the hopper described above, it is possible to send even a very small amount of material or an extremely thin tube by replacing and purging with a replacement gas. Pneumatic transport system for materials characterized by   The replacement gas supply path is branched and connected to the chute, feeder, and hopper, and is branched on the primary side of the purge pressure regulator, and is also connected to the venturi. A pneumatic transport system for a material according to claim 1.   3. The pneumatic transportation system for materials according to claim 1, wherein the chute has a double pipe structure.   4. The material pneumatic transport system according to claim 1, wherein the replacement of the air and the replacement gas is performed at the same pressure.   5. The pneumatic transportation system for a material according to claim 1, wherein the material discharged from the venturi is transported as a mixed gas with a replacement gas.   6. The material pneumatic transport system according to claim 1, wherein the replacement gas is an inert gas.

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