JP2013169701A - Powder and grain processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure capable of suppressing charging adhesion of powder and grain to an inner surface of a window portion, in a powder and grain processing device including the window portion made of glass.SOLUTION: A powder and grain processing device includes a casing having an inner space for carrying or temporarily storing powder and grain 9. The casing includes a glass window portion 40 at least partially installed. An inner surface 41 of the window portion 40 is at least partially a roughened uneven surface. This reduces a contact area between the inner surface 41 of the window portion 40 and the powder and grain 9. Thus, charging adhesion of the powder and grain 9 to the inner surface 41 of the window portion 40 is suppressed.

Description

  The present invention relates to a powder processing apparatus for conveying or temporarily storing a powdery or granular material (hereinafter referred to as “powder”).

  Conventionally, a granular material processing apparatus having a casing for conveying or temporarily storing granular material is known. For example, Patent Literature 1 describes a pellet supply apparatus having a hopper that stores pellets and a sight glass connected to the hopper (Claim 1, FIG. 1). In the pellet supply apparatus of Patent Document 1, pellets stored in the hopper are supplied to the molding apparatus through the sight glass. Moreover, in patent document 1, the electrostatic capacitance type sensor for detecting a pellet is arrange | positioned outside the sight glass (paragraph 0056, FIG. 1).

JP 2010-113838 A

  A granular material such as a pellet may be charged by colliding with an inner surface of a pipe or a hopper during conveyance. On the other hand, glass has the property of being easily charged to +. For this reason, when a part of powder processing apparatus is formed with glass (for example, when it has a sight glass like patent document 1), the granular material charged to-on the inner surface of the glass concerned There is a problem that it is easy to adhere.

  When the granular material adheres to the glass surface, it becomes difficult to visually recognize the state of the internal granular material through the glass. In addition, the granular material adhering to the glass causes a malfunction of the sensor. In addition, if the granular material attached to the glass falls as a lump or is mixed into a subsequent granular material, the uniformity of the granular material supplied to the molding machine is lowered. As a result, the quality of the resin product may be adversely affected.

  In this regard, in Patent Document 1, static charges in the sight glass are removed using a static eliminator (claim 1, paragraph 0052). However, if it is intended to prevent the adhesion of the powder particles to the glass surface using only the static eliminator, energy for operating the static eliminator is accordingly required.

  An object of the present invention is to provide a structure capable of suppressing charging and adhering of a granular material to an inner surface of a window portion while reducing energy consumption in a granular material processing apparatus having a glass window portion.

  In order to solve the above-mentioned problem, the first invention of the present application is a powder processing apparatus, comprising a casing having an internal space for conveying or temporarily storing the powder, wherein the casing is at least partially The window portion made of glass is provided, and the inner side surface of the window portion is at least partially a rough surface subjected to a roughening treatment.

  2nd invention of this application is a granular material processing apparatus of 1st invention, Comprising: The average space | interval of the adjacent convex crest parts of the said uneven surface is smaller than the average particle diameter of a granular material.

  3rd invention of this application is a granular material processing apparatus of 1st invention or 2nd invention, Comprising: The detection which detects the presence or absence of the granular material in the predetermined height position in the said casing via the said window part And the uneven surface is provided on at least a portion of the inner side surface of the window overlapping the detection area of the detection means.

  4th invention of this application is a granular material processing apparatus of 3rd invention, Comprising: The said detection means is an electrostatic capacitance type sensor.

  5th invention of this application is a granular material processing apparatus in any one from 1st invention to 4th invention, Comprising: The inner surface of the said window part is the uneven surface and the flat surface which is not roughened. And both.

  A sixth invention of the present application is any one of the granular material processing apparatuses from the first invention to the fifth invention, wherein the casing conveys or stores the granular material without actively heating the granular material.

  According to the first to sixth inventions of the present application, the contact area between the inner surface of the window and the granular material is reduced. For this reason, the electrification adhesion of the granular material with respect to the inner surface of a window part is suppressed.

  In particular, according to the second invention of the present application, it is possible to prevent the granular material from entering between the convex top portions of the uneven surface. Thereby, adhesion of the granular material to an uneven surface can further be suppressed.

  In particular, according to the third invention of the present application, it is possible to suppress erroneous detection of powder particles by the detection means.

  In particular, according to the fourth invention of the present application, even if the light transmittance of the casing is lowered due to the uneven surface, the granular material can be detected with high accuracy.

  In particular, according to the fifth aspect of the present invention, the visibility inside the casing can be secured.

  In particular, according to the sixth invention of the present application, it is possible to suppress thermal fusion of the granular material to the inner side surface of the casing.

It is a longitudinal cross-sectional view of a pellet supply apparatus. It is a fragmentary longitudinal cross-sectional view of the inner peripheral surface vicinity of a glass tube. It is a perspective view of a glass tube and a level sensor. It is a longitudinal cross-sectional view of a pellet supply apparatus.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

<1. First Embodiment>
FIG. 1 is a vertical cross-sectional view of a pellet supply apparatus 1 as an example of a powder particle processing apparatus according to the present invention. This pellet supply apparatus 1 is installed in the upper part of the molding machine 2 which injection-molds a resin product. The pellet supply device 1 is a device that sucks and transports resin pellets 9 that are powder particles from a material supply source 21 and supplies the resin pellets 9 to the molding machine 2. As shown in FIG. 1, the pellet supply apparatus 1 of the present embodiment includes a hopper 10, a material supply pipe 20, a suction mechanism 30, a glass tube 40, a level sensor 50, and a control unit 60.

  The hopper 10 has a substantially cylindrical side wall 11 and a bottom 12 that gradually converges downward from the lower end of the side wall 11. The upper part of the hopper 10 is closed by a substantially flat cover 70. The hopper 10 and the cover 70 are made of a metal such as stainless steel or iron, for example. The cover 70 is provided with a loading port 71 penetrating vertically. The material supply pipe 20 is connected in communication with the input port 71 of the cover 70. The upstream end of the material supply pipe 20 is connected to the material supply source 21.

  The suction mechanism 30 has a suction tube 31 and a vacuum pump 32. The suction pipe 31 connects the suction port 111 provided in the side wall 11 of the hopper 10 and the vacuum pump 32. When the vacuum pump 32 is operated, the air inside the hopper 10 is sucked into the suction pipe 31, and the inside of the hopper 10 becomes negative pressure. Then, the resin pellet 9 is sucked and transported from the material supply source 21 through the material supply pipe 20 into the hopper 10.

  The internal space of the hopper 10 is wider than the internal space of the material supply pipe 20. For this reason, when the resin pellet 9 sucked and transported passes through the inlet 71 and enters the hopper 10, the resin pellet 9 is decelerated. The suction port 111 is provided with a filter 13 having a large number of pores. Air inside the hopper 10 is sucked into the suction pipe 31 through the filter 13. On the other hand, the resin pellet 9 falls to the lower part of the hopper 10 without passing through the filter 13.

  The glass tube 40 is a glass member that extends vertically in a cylindrical shape. The upper end portion of the glass tube 40 is attached to a discharge port 121 provided in the bottom portion 12 of the hopper 10. On the other hand, the lower end portion of the glass tube 40 is connected to the molding machine 2 via the connection portion 80. As shown in FIG. 1, the resin pellets 9 that have dropped from the hopper 10 are stored inside the glass tube 40. That is, in this embodiment, the glass tube 40 is a casing having an internal space for temporarily storing the resin pellets 9.

  When the molding process proceeds in the molding machine 2, resin pellets 9 are supplied from the glass tube 40 to the molding machine 2 accordingly. If it does so, the position of the upper surface of the resin pellet 9 stored inside the glass tube 40 will fall. The user of the pellet supply apparatus 1 can visually recognize the state of the resin pellet 9 stored inside through the glass tube 40 from the outside. That is, the glass tube of this embodiment plays the role of sight glass, and the whole becomes a window part.

  The level sensor 50 is disposed in the vicinity of the outer peripheral surface of the glass tube 40. The level sensor 50 detects the presence or absence of the resin pellet 9 at a predetermined height position inside the glass tube 40 through the glass tube 40. For the level sensor 50, for example, a capacitive proximity sensor may be used.

  As conceptually shown in FIG. 1, the control unit 60 is electrically connected to the vacuum pump 32 and the level sensor 50. The control unit 60 may be configured by a computer having an arithmetic processing unit such as a CPU and a memory, or may be configured by an electronic circuit. The control unit 60 receives the detection signal generated by the level sensor 50 and controls the driving of the vacuum pump 32 based on the detection signal. Thereby, the transport amount of the resin pellet 9 is controlled, and the height position of the upper surface of the resin pellet 9 stored in the glass tube 40 is maintained within a predetermined range.

  The glass tube 40 is suitable for storing granular materials in terms of strength, durability, visibility, and the like, but has a property of being easily charged to +. In addition, the resin pellet 9 may be charged by colliding with the material supply pipe 20 or the inner surface of the hopper 10 in the transport route to the glass tube 40. For this reason, in this embodiment, in order to suppress charging adhesion of the resin pellet 9 to the inner peripheral surface 41 of the glass tube 40, the inner peripheral surface 41 of the glass tube 40 is roughened.

  FIG. 2 is a partial longitudinal sectional view of the vicinity of the inner peripheral surface 41 of the glass tube 40. In the present embodiment, the inner peripheral surface 41 of the glass tube 40 is subjected to blasting such as sandblasting. As a result, the entire inner peripheral surface 41 of the glass tube 40 is a uniform uneven surface. If the inner peripheral surface 41 of the glass tube 40 is an uneven surface, the contact area between the inner peripheral surface 41 and the resin pellet 9 is reduced. Therefore, even if the glass tube 40 is positively charged and the resin pellet 9 is negatively charged, the adhesion of the resin pellet 9 to the inner peripheral surface 41 of the glass tube 40 is suppressed.

  If adhesion of the resin pellet 9 with respect to the glass tube 40 is suppressed, it can suppress that the visibility inside the glass tube 40 falls. Further, malfunction of the level sensor 50 due to adhesion of the resin pellet 9 can also be suppressed. Furthermore, the possibility that the resin pellets 9 attached to the glass tube 40 may fall as a lump or be mixed into subsequent resin pellets and adversely affect the quality of the resin product can be reduced.

  As shown in FIG. 2, the inner peripheral surface 41 of the glass tube 40 has a plurality of convex top portions 413. Moreover, in this embodiment, the average space | interval d1 of adjacent convex peak parts 413 is smaller than the average particle diameter of the resin pellet 9. FIG. If it does in this way, it can control that resin pellet 9 enters between a plurality of convex top parts 413. FIG. As a result, it is possible to further suppress the resin pellet 9 from adhering to the inner peripheral surface 41 of the glass tube 40.

  As shown in FIG. 2, when the shape of the resin pellet 9 is not spherical, attention is paid to the smallest diameter r2 among the plurality of diameters r1 and r2 of the resin pellet 9, and the convexity is larger than the average value of the diameter r2. It is preferable to set the average interval d1 of the top portions 413 small.

  Since the inner peripheral surface 41 of the glass tube 40 is an uneven surface, a part of light is diffusely reflected. However, in the present embodiment, the roughening treatment is performed to such an extent that the visibility inside the glass tube 40 is not completely impaired by irregular reflection. Therefore, the glass tube 40 retains the function as a sight glass, and the user of the pellet supply apparatus 1 can confirm the upper surface position of the resin pellet 9 stored inside the glass tube 40 from the outside.

  In addition, the roughening process may be given only to a part of inner peripheral surface of the glass tube. For example, as shown in FIG. 3, the inner peripheral surface 41 </ b> A of the glass tube 40 </ b> A may have both a rough surface 411 </ b> A that has been roughened and a flat surface 412 </ b> A that has not been roughened. . In the example of FIG. 3, the concavo-convex surface 411A is provided in a region overlapping the detection area 51A of the level sensor 50A. In this way, it is possible to suppress adhesion of resin pellets at least in the detection area 51A of the level sensor 50A. Therefore, erroneous detection of resin pellets by the level sensor 50A can be suppressed.

  In the example of FIG. 3, the visibility is not deteriorated on the flat surface 412 </ b> A that is not roughened. Therefore, even if it is difficult to visually recognize the inside through the concavo-convex surface 411A, the state of the resin pellets stored inside can be easily confirmed through the flat surface 412A.

<2. Second Embodiment>
FIG. 4 is a longitudinal sectional view of a pellet supply apparatus 1B as another example of the granular material processing apparatus according to the present invention. The pellet supply device 1B is a device that temporarily stores the resin pellets 9B that are powder particles in the hopper 10B, and then supplies the resin pellets 9B to the subsequent device 2B in a necessary amount. As shown in FIG. 1, the pellet supply apparatus 1B according to the present embodiment includes a hopper 10B, a material supply pipe 20B, a suction mechanism 30B, a level sensor 50B, and a control unit 60B.

  The hopper 10B has a substantially cylindrical side wall 11B and a bottom 12B that gradually converges downward from the lower end of the side wall 11B. The upper part of the hopper 10B is closed by a substantially flat cover 70B. The hopper 10B and the cover 70B are made of, for example, a metal such as stainless steel or iron. A space for temporarily storing the resin pellet 9B is formed in the hopper 10B.

  The material supply pipe 20B is connected in communication with a charging port 111B provided in the side wall 11B of the hopper 10B. The upstream end of the material supply pipe 20B is connected to the material supply source 21B.

  The suction mechanism 30B has a suction tube 31B and a vacuum pump 32B. The suction tube 31B connects the suction port 71B provided in the cover 70B and the vacuum pump 32B. When the vacuum pump 32B is operated, the air inside the hopper 10B is sucked into the suction pipe 31B, and the inside of the hopper 10B becomes negative pressure. Then, the resin pellet 9B is sucked and transported from the material supply source 21B through the material supply pipe 20B to the inside of the hopper 10B.

  The internal space of the hopper 10B is wider than the internal space of the material supply pipe 20B. For this reason, the resin pellet 9B sucked and transported decelerates when it passes through the inlet 111B and enters the hopper 10B. Further, a filter 13B having a large number of pores is provided on the upper portion of the hopper 10B. The air inside the hopper 10B is sucked into the suction pipe 31B through the filter 13B. On the other hand, the resin pellet 9B is stored inside the hopper 10B without passing through the filter 13B.

  Thus, in the present embodiment, the hopper 10B is a casing having an internal space for temporarily storing the resin pellets 9B. A discharge port 121B is provided at the bottom 12B of the hopper 10B. The resin pellets 9B stored in the hopper 10B are supplied to the subsequent apparatus 2B via the discharge port 121B.

  In the present embodiment, a glass window portion 14B is provided in a part of the side wall 11B of the hopper 10B. The user of the pellet supply apparatus 1B can visually recognize the state of the resin pellet 9B stored in the hopper 10B from the outside through the window portion 14B.

  The level sensor 50B is disposed in the vicinity of the outer surface of the window portion 14B. The level sensor 50B detects the presence or absence of the resin pellet 9B at a predetermined height position inside the hopper 10B through the window portion 14B. For example, a capacitive proximity sensor may be used as the level sensor 50B.

  As conceptually shown in FIG. 3, the control unit 60B is electrically connected to the vacuum pump 32B and the level sensor 50B. The control unit 60B may be configured by a computer having an arithmetic processing unit such as a CPU and a memory, or may be configured by an electronic circuit. The control unit 60B receives the detection signal generated by the level sensor 50B, and controls the driving of the vacuum pump 32B based on the detection signal. Thereby, the transport amount of the resin pellet 9B is controlled, and the height position of the upper surface of the resin pellet 9B stored in the hopper 10B is maintained within a predetermined range.

  Glass is suitable as a material for the window portion 14B in terms of strength, durability, visibility, and the like, but has a property of being easily charged to +. In addition, the resin pellet 9B may be charged by colliding with the inner surface of the material supply pipe 20B in the transport route to the hopper 10B. For this reason, in this embodiment, in order to suppress charging adhesion of the resin pellet 9B to the inner side surface 141B of the window part 14B, the inner side surface 141B of the window part 14B is subjected to a roughening process.

  Specifically, the inner surface 141B of the window portion 14B may be subjected to a blasting process such as sandblasting so as to have an uneven surface similar to that shown in FIG. If the inner side surface 141B of the window portion 14B is an uneven surface, the contact area between the inner side surface 141B and the resin pellet 9B is reduced. Therefore, even if the window portion 14B is positively charged and the resin pellet 9B is negatively charged, the charging adhesion of the resin pellet 9B to the inner surface 141B of the window portion 14B is suppressed.

  If adhesion of the resin pellet 9B to the window portion 14B is suppressed, it is possible to suppress a decrease in visibility inside the hopper 10B by the window portion 14B. Further, malfunction of the level sensor 50B due to the adhesion of the resin pellet 9B can be suppressed. Furthermore, the possibility that the resin pellets 9B adhering to the window portion 14B may fall as a lump or be mixed into subsequent resin pellets to adversely affect the quality of the resin product can be reduced.

  Also in the present embodiment, as in FIG. 2, it is preferable that the average interval between the adjacent convex crests on the inner surface of the window portion 14B is smaller than the average particle size of the resin pellet 9B. Moreover, it is preferable that the roughening process of the window part 14B is performed to such an extent that the visibility inside the hopper 10B is not impaired completely by the irregular reflection of light. Moreover, the roughening process may be performed only to a part of inner surface of the window part 14B.

<3. Modification>
The first embodiment and the second embodiment of the present invention have been described above, but the present invention is not limited to the above embodiment.

  The detection means of the present invention may be a capacitance type sensor that has appeared in the above embodiments, or may be a sensor of another type. For example, a reflective or transmissive optical sensor using a phototube may be used in place of the capacitive sensor. However, a capacitance type sensor is preferable in that it can detect the presence or absence of a granular material with high accuracy even if the light transmittance of the window portion is reduced due to the uneven surface.

  Moreover, the granular material processing apparatus of this invention may be further equipped with the other means for suppressing the electrification adhesion of a granular material. For example, a static eliminator for removing an electrostatic charge may be further disposed inside the casing. Further, a mechanism for supplying ionized gas to the granular material may be further provided to reduce charging of the granular material.

  Moreover, the granular material processing apparatus of this invention may perform processes, such as stirring and measurement, with respect to the granular material stored inside the casing. However, when a process involving heating is performed on a granular material such as a resin pellet, a problem of adhesion different from charging adhesion occurs in which the granular material is thermally fused to the inner surface of the casing. Therefore, it is preferable that the process performed in a casing is a non-heating process which does not involve an active heating. Further, the casing of the present invention may be a pipe that conveys the granular material without storing it inside.

  Moreover, the granular material processing apparatus of this invention may handle powdery or granular materials other than resin pellets.

  Moreover, about the detailed shape of a granular material processing apparatus, you may differ from the shape shown by each figure of this application.

  Moreover, you may combine suitably each element which appeared in said embodiment and modification in the range which does not produce inconsistency.

<4. Invention of Other Viewpoint>
If “suppressing erroneous detection of powder particles by the detection means” is set as the first problem, the “glass window” is not an indispensable requirement. Instead, the “detection means” is indispensable. The invention as a requirement can be extracted from the above embodiment. The invention includes, for example, “a casing for temporarily storing powder particles, and detection means for detecting the presence or absence of powder particles at a predetermined height position in the casing, Among them, a granular material processing apparatus in which at least a portion that overlaps the detection area of the detection means is a roughened uneven surface.

  According to this invention, it can suppress that the charged granular material adheres to the inner surface of a casing. Therefore, the erroneous detection of the granular material by the detection means can be suppressed. Moreover, it is also possible to combine each element which appeared in said embodiment and modification in this invention.

DESCRIPTION OF SYMBOLS 1,1B Pellet supply apparatus 2 Molding machine 2B Subsequent apparatus 9,9B Resin pellet 10,10B Hopper 11,11B Side wall 12,12B Bottom part 13,13B Filter 14B Window part 20,20B Material supply pipe 21,21B Material supply source 30 , 30B Suction mechanism 31, 31B Suction tube 32, 32B Vacuum pump 40, 40A Glass tube 41, 41A Inner side surface 50, 50A, 50B Level sensor 51A Detection area 60, 60B Control unit 70, 70B Cover 80 Connection unit 141B Inner side surface 411A Uneven surface 412A Flat surface 413 Convex top

Claims (6)

Comprising a casing having an internal space for conveying or temporarily storing powder particles;
The casing has a glass window portion provided at least partially,
The granular material processing apparatus in which the inner surface of the said window part is the uneven | corrugated surface by which the roughening process was carried out at least partially. It is a granular material processing apparatus of Claim 1, Comprising:
The granular material processing apparatus whose average space | interval of the adjacent convex crest parts of the said uneven surface is smaller than the average particle diameter of a granular material. It is the granular material processing apparatus according to claim 1 or 2,
Further comprising a detecting means for detecting the presence or absence of powder particles at a predetermined height position in the casing through the window,
The irregular surface is a powder processing apparatus provided on at least a portion of the inner side surface of the window that overlaps the detection area of the detection means. It is a granular material processing apparatus of Claim 3, Comprising:
The detection means is a granular material processing apparatus which is a capacitance type sensor. It is the granular material processing apparatus according to any one of claims 1 to 4,
The granular material processing apparatus in which the inner surface of the said window part has both the said uneven | corrugated surface and the flat surface which is not roughened. It is the granular material processing apparatus according to any one of claims 1 to 5,
The said casing is a granular material processing apparatus which conveys or stores a granular material, without heating positively.

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