JP6465739B2 - Powder supply device - Google Patents

Description

  The present invention relates to a novel powder supply apparatus. In detail, when supplying a granular material to a to-be-supplied part, the supply apparatus of the granular material which can prevent consolidation of the granular material in a to-be-supplied part is provided.

  The operation of supplying the granular material existing in the hopper to the supply target existing therebelow is performed at various locations in the industrial manufacturing process.

  For example, when the resin is supplied to an extruder and melt-kneaded, the resin is supplied from a hopper present in the upper part of the extruder through a supply pipe to a supply port of the extruder that is a supply portion. The resin supplied to the extruder is sent into a cylinder by a screw of the extruder, pressurized while being heated and melted, and extruded from a die to be molded.

  However, in the above operation, the resin supplied from the hopper to the supply port of the extruder is not sufficiently caught in the screw, and the amount of resin supplied into the cylinder is reduced, and further, the amount of extrusion from the die is reduced. A phenomenon may occur. It has been confirmed by the present inventor that such a phenomenon frequently occurs particularly when the resin is in a form having high fluidity such as pellets.

  As a result of studying the above phenomenon, the present inventor has found that the amount of excess air entrained in the screw is large, and the excess air forms an air layer that acts as a heat insulating layer when the resin is heated in the cylinder. It has been found that when the filling rate of the resin supplied to the screw portion through the supply port of the extruder is high, the discharge from the system is hindered.

  In addition, when supplying the granular material present in the hopper to the supplied part, due to the acceleration when the granular substance falls, abnormally pressure is applied to the supplied part, and the supplied granular material is consolidated, The knowledge that the filling rate is increased was obtained.

  Such a consolidation phenomenon is not limited to the case where the resin is supplied to the extruder, and there is a concern that the consolidation phenomenon may occur when other powder particles are handled.

  Accordingly, an object of the present invention is to provide a granular material supplying apparatus that supplies a granular material existing in a hopper to a supply portion existing below the hopper. An object of the present invention is to provide a granular material supply device capable of preventing compaction of granular material in a supply portion by reducing the pressure at the time.

  As a result of repeated studies to solve the above-mentioned problems, the present inventor can prevent the accumulation of granular materials in the granular material supply pipe provided between the hopper and the supplied portion located below the hopper. After providing a member whose upper surface is inclined to an extent and colliding at least a part of the granular material falling in the pipe, the granular material applied to the supplied portion is supplied to the supplied portion. It has been found that the pressure at the time of dropping can be effectively reduced, and the present invention has been proposed.

In other words, according to the present invention, at least a part of the granular material falling from the hopper and the supplied part located below the hopper is brought into contact with the supplied granular material. A pressure reducing member having an inclined upper surface is provided to reduce the pressure when the granular material falls on the part, and further, the granular material supply pipe is expanded downward from a position where the pressure reducing member exists. There is provided a supply apparatus for a granular material, characterized in that a gas purge nozzle is provided on a diameter transition surface up to the enlarged portion .

In the above invention, the pressure reducing member is formed of a member having a conical upper surface, and a gap through which the granular material can pass between the outer periphery of the member and the inner wall of the pipe is provided over the entire periphery. It is preferable for supplying the powder particles uniformly to the supply unit .

  Further, it is preferable that the inclination angle of the upper surface of the pressure reducing member is set larger than the angle of repose of the granular material in order to prevent the granular material from staying on the pressure reducing member.

  According to the granular material supply apparatus of the present invention, the pressure reducing member is provided in the granular material supply pipe, and a part of the granular material falling in the granular material supply pipe from the hopper is used as the pressure reducing member. By making it collide, it can prevent effectively that the fall pressure of the granular material from a hopper applies to a supplied part directly, and can prevent the compaction of the granular material in a supplied part effectively.

  Therefore, when the supply device of the granular material of the present invention is applied to the mode of supplying the resin to the extruder, the resin is prevented from being consolidated in the raw material supply portion of the extruder corresponding to the supplied portion, thereby forming Since the excess air is sufficiently discharged from the gaps between the formed powder and granule, the amount of air biting into the resin in the extruder can be reduced, and as a result, a stable extrusion amount from the die is secured. can do.

  The granular material supply device of the present invention is particularly effective when handling a granular material having good fluidity. When the granular material, specifically, a resin pellet, The effect is particularly remarkable.

It is the schematic which shows the typical aspect of the supply apparatus of the granular material of this invention. It is the schematic which shows the one aspect | mode of the pressure reduction member in this invention. It is the schematic which shows the other one aspect | mode of the pressure reduction member in this invention.

  Hereinafter, the present invention will be described in detail with reference to FIG. 1 showing a typical embodiment of the present invention, but the present invention is not limited to FIG.

  The granular material supply apparatus according to the present invention is in contact with the granular material dropping the pipe 3 in the granular material supply pipe 3 provided between the hopper 1 and the supplied portion 2 positioned below the hopper 1. A gap d through which the granular material can flow down is provided between the pressure reducing member 4 having an inclined upper surface and the inner wall of the pipe for reducing the pressure when the granular material falls on the supplied part. It is characterized by being provided.

  In the present invention, the hopper 1 has at least an inclined surface equal to or greater than the angle of repose of the granular material handled in the lower part, and has a known structure having a discharge port connected to the granular material supply pipe without particular limitation. Is done.

  Moreover, the granular material supply piping 3 will not be restrict | limited especially if it is a straight pipe which connects the said hopper 1 and the to-be-supplied part 2. FIG.

  In addition, although the internal diameter (diameter) and length of the said granular material supply piping are based also on the magnitude | size of an apparatus, an internal diameter is 50-200 mm, length is 0.5 or more, Especially about 0.5-2 m is common. Is. The effect of the present invention becomes more prominent as the length of the powder supply pipe is longer, but the consolidation phenomenon occurs even in a relatively short pipe length of 0.5 to 2 m, and the present invention It has been clarified by the inventor's examination that such a phenomenon can be prevented by applying.

  The greatest feature of the present invention is that the pressure at the time of dropping of the granular material applied to the portion to be supplied 2 is reduced by bringing at least a part of the granular material falling through the piping 3 into contact with the granular material supplying pipe 3. This is because a pressure reducing member 4 having an inclined upper surface is provided.

  The inclined upper surface of the pressure reducing member 4 causes the powder particles falling from the hopper to collide with the pressure reducing member 4 to significantly reduce the pressure applied to the supplied portion as compared with the case where the powder particles fall directly on the supplied portion. And it has a function which prevents the consolidation in such a location.

  The pressure reducing member is not particularly limited as long as it has such a function, but as a typical aspect, the granular material flows down between the pressure reducing member 4 having an inclined upper surface and the inner wall of the pipe. An embodiment in which a gap is provided, specifically, as shown in FIG. 1, a member having a conical upper surface is used as the pressure reducing member 4, and a powder is formed between the outer periphery of the member and the inner wall of the pipe. A mode in which a gap d through which the granular material can pass is formed so as to be formed over the entire circumference, a mode in which a member made of an inclined plate-like body is provided so as to form a gap d with the inner wall of the pipe 3 as shown in FIG. Is mentioned. Among these, the embodiment shown in FIG. 1 is preferable for uniformly supplying the granular material to the supplied portion.

  The gap d has only to be formed with a width that does not block the granular material in the pipe. Generally, the gap d is 10 to 40%, preferably 15 to 30 with respect to the diameter of the granular material supply pipe to be attached. % Gap is preferably formed.

  Further, as shown in FIG. 3, the pressure reducing member 4 may be formed of a spiral plate-like body as an inclined surface, and the entire amount of powder particles collide with the inclined surface and slide down. is there.

  In the present invention, the position where the pressure reducing member 4 is provided is preferably as close to the supplied part as possible. For example, the length (L) of the granular material supply pipe 3, that is, the hopper lower end and the supplied part In general, it is preferable that the upper end of the inclined surface is provided at a position below L / 2, preferably at a position below L / 3.

  Further, the angle θ of the inclined surface of the pressure reducing member 4 is preferably set to an angle equal to or greater than the repose angle of the target granular material in order to prevent the granular material from accumulating on the surface. On the other hand, when the angle of the inclined surface is extremely large, the pressure reduction effect tends to decrease, so it is desirable that the upper limit is 75 °, particularly 60 °. Specifically, the resin pellets are preferably 30 ° to 60 °, particularly 45 ° to 50 °.

  Further, the means for attaching the pressure reducing member 4 to the granular material supply pipe is not particularly limited. When the pressure reducing member 4 is made of a member having the conical upper surface, two or more vertical ribs are attached to the surrounding wall at any place. The method of fixing is mentioned.

  In the present invention, when the supplied part is an extruder and the extruder does not have a gas purge nozzle in the pipe, the excess air is discharged from the upper part of the hopper, but the excess air is discharged by the granular material flowing down in the pipe. The upward flow may be hindered. In such a case, forming the enlarged portion 5 below the position where the pressure reducing member is present, and providing the gas purge nozzle 7 on the diameter transition surface 6 leading to the enlarged portion is accompanied with the granular material. This is preferable in order to reduce the amount of air supplied.

  The granular material supply apparatus of the present invention is particularly effective for a granular material having good fluidity. Specifically, it is substantially spherical and is effective for a granular material having an angle of repose of 60 ° or less, particularly 45 ° or less. The particle size (equivalent diameter) of the powder is generally 0.01 to 15 mm, particularly about 0.1 to 10 mm. More specifically, the powder particle supply apparatus of the present invention can be suitably used for the resin pellets having the angle of repose and the particle diameter.

  1 is used to supply resin pellets having an average particle diameter of 4.0 mm (an angle of repose of 45 °) to the extruder serving as the supplied portion 2 in an amount of 7 kg / min. Extrusion was performed.

In the above powder and particle supply apparatus, the discharge port of the hopper 1 of 0.1 m ³ and the supply port of the extruder located 750 mm below the discharge port have a diameter of 100 mm (length 60 mm, diameter 170 mm) 5)). A gas purge nozzle 7 is provided on the diameter transition surface that reaches the enlarged portion.

  The pressure relief member 4 having a diameter of 60 mm and an inclination angle of 45 ° on the upper surface having a conical shape on the upper surface is positioned at a height of 250 m from the supply port of the extruder. Fixed to be uniform.

  When extrusion molding was carried out using the above-mentioned granular material supply device, the amount of resin discharged from the die remained stable with little change during extrusion molding of the resin 1t.

  On the other hand, as a result of resin extrusion molding under the same conditions except that the pressure reducing member 4 is not provided, the amount of resin discharged from the die is reduced and the resin supply from the hopper is stopped. There has occurred.

DESCRIPTION OF SYMBOLS 1 Hopper 2 Supply part 3 Granule supply pipe 4 Pressure reduction member 5 Enlarged part 6 Diameter transition surface 7 Gas purge nozzle

Claims (5)

Dropping of the granular material applied to the supplied part by bringing at least a part of the granular material falling through the pipe into contact with the granular material supply pipe provided between the hopper and the supplied part located below the hopper A pressure reducing member having an inclined upper surface for reducing pressure at the time, and further, the powder supply pipe has an enlarged portion below a position where the pressure reducing member exists, and the enlarged portion A granular material supply apparatus , wherein a gas purge nozzle is provided on a diameter transition surface up to .   The powder according to claim 1, wherein the pressure reducing member is made of a member having a conical upper surface, and is provided with a gap through which a granular material can pass between an outer periphery of the member and an inner wall of the pipe. Granule supply device.   The supply device of the granular material according to claim 1 or 2, wherein an inclination angle of an upper surface of the pressure reducing member is set larger than an angle of repose of the granular material. The granular material supply apparatus according to any one of claims 1 to 3 , wherein the target granular material is substantially spherical. The granular material supply apparatus according to any one of claims 1 to 4 , wherein the target granular material is a resin pellet, and the supply target is a supply port of an extruder.

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