JP3712185B2 - Fine powder material supply equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fine powder raw material supply apparatus for supplying the fine powder raw material to an extruder for mixing and extruding a fine powder raw material having a small bulk density to a polymer.
[0002]
[Prior art]
An example of a conventional fine powder raw material supply apparatus used in an extruder for extruding a polymer by mixing a fine powder raw material with a small bulk density will be described.
[0003]
As shown in FIG. 6, the extruder 201 is heated and Cylinders 202, and two screws 203 of intermeshing rotatably disposed within the heating cylinder 202, two screw 203 same or opposite A rotation drive mechanism (not shown) for rotating in the direction, and a fine material feed port 204 provided on the side wall of the heating cylinder 202 on the upstream side of the kneading section.
[0004]
On the other hand, the fine powder raw material supply apparatus 101 includes a barrel 102 having a discharge port 102a at the front end and a hopper 104 at the rear end side, and two meshing type screws 103 rotatably disposed in the barrel 102, A rotary drive mechanism 105 that rotates the two screws 103 in the same direction or in the opposite direction is provided. The hopper 104 is provided with a gas vent port 106, and the discharge port 102 a of the barrel 102 is a heating cylinder 202 in the extruder 201. To the fine powder raw material supply port 204.
[0005]
In this conventional fine powder raw material supply apparatus 101, the fine powder raw material charged into the hopper 104 rotates in the same direction or in the reverse direction within the barrel 102 after the mixed air is forcibly exhausted through the gas vent 106. It is transferred to the tip side by the two screws 103, supplied into the heating cylinder 201 from the discharge port 102a via the fine powder material supply port 204 of the extruder 201, mixed with the polymer in the extruder 201, and then extruded.
[0006]
[Problems to be solved by the invention]
In the above conventional technology, air mixed in the fine powder material supplied to the hopper is forcibly exhausted through the vent hole provided in the hopper, but this alone sufficiently removes the air mixed in the fine powder material. The amount of air mixed in the fine powder raw material in the hopper increases, the bulk density of the fine powder raw material is reduced, and the substantial fine powder raw material transport capability of the fine powder raw material supply device is reduced. As a result, the supply amount of the fine powder raw material to the extruder becomes unstable. In addition, if the volatile component in the polymer is gasified in the extruder and flows back into the barrel of the fine powder raw material supply apparatus, there is a problem that the transport capability of the fine powder raw material supply apparatus is extremely reduced.
[0007]
The present invention has been made in view of the above-described problems of the prior art, and sufficiently forcibly exhausts air and gas mixed in the fine powder raw material in the barrel to stably maintain a high transport capability. An object of the present invention is to realize a fine powder raw material supply device for supplying the fine powder raw material to an extruder that can mix and extrude a fine powder raw material having a low bulk density into a polymer.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the fine powder raw material supply apparatus of the present invention is a fine powder raw material supply apparatus for supplying the fine powder raw material to an extruder that mixes and extrudes a fine powder raw material having a small bulk density to a polymer. The fine raw material supply device has a discharge port connected to a fine powder raw material supply port provided on a side wall of the heating cylinder of the extruder at one end and a barrel having a hopper at the other end, and is rotatable in the barrel. An arranged screw, a rotation drive mechanism for rotating the screw, and at least two vent ports provided through the wall between the hopper and the discharge port in the barrel from the outer wall surface to the inner wall surface ; wherein the forcible exhaust chamber communicating with the barrel outer wall side opening of the vent port, and a screen unit mounted to the vent in the opening, wherein the screen unit, the A perforated plate-like curved wall that is substantially flush with the inner wall surface of the rel, a box-shaped receiving member having an open surface facing the curved wall, and an average particle size of the fine powder raw material that covers the curved wall A screen having a mesh, and a pressing member having a grid-like pressing plate for bringing the screen into close contact with the curved wall of the receiving member and forming a vent channel are provided.
[0009]
In addition, a cooling jacket for flowing a cooling medium is provided in the wall of the barrel.
[0010]
Further, one end side of the air supply duct is connected to the forced exhaust chamber via the air supply valve, and the pressurized air or inert gas is instantaneously supplied through the air supply duct to reversely clean the screen. Configure to be able to.
[0011]
A pressure gauge for detecting the internal pressure is attached to the forced exhaust chamber.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of a fine powder raw material supply apparatus according to the present invention will be described.
[0013]
As shown in FIG. 1, the fine powder raw material supply apparatus 1 includes a barrel 2 having a discharge port 2 a at the front end and a hopper 4 provided at the rear end side, and a meshing type rotatably disposed in the barrel 2. A fine powder raw material supply provided with two screws 3 and a rotary drive mechanism 5 for rotating the two screws 3 in the same direction or in the opposite direction, and the discharge port 2a provided on the side wall of the heating cylinder 42 of the extruder 41. It is arranged in communication with the port 44.
[0014]
As shown in FIG. 2, a vent port 8 penetrating from the outer wall surface to the inner wall surface is provided on both side walls of the barrel 2 between the discharge port 2 a and the hopper 4. Is equipped with a screen unit 10 which will be described later, and the opening on the outer wall surface side of each vent port 8 communicates with the forced exhaust chamber 20.
[0015]
Further, a cooling jacket 6 is provided in the wall of the barrel 2 avoiding the vent port 8 so that when the fine powder material has a low melting point, the cooling jacket 6 can be cooled by flowing a cooling medium. It is configured.
[0016]
Each forced exhaust chamber 20 is connected to one end side of an exhaust duct 22 via an exhaust valve 21, and the other end side of the exhaust duct 22 is connected to forced exhaust means (not shown).
[0017]
In the present embodiment, each forced exhaust chamber 20 is connected to one end side of an air supply duct 24 via an air supply valve 23.
[0018]
Each forced exhaust chamber 20 is provided with a viewing window 26 for observing the inside and a pressure gauge 25 for detecting the internal pressure.
[0019]
Further, a pressure gauge 27 is provided on the downstream side of the vent port 8 in the barrel 2, and when an abnormal pressure in the barrel 2 is detected by the pressure gauge, a safety measure is taken such as sending a signal to the control system to stop the operation. Can be used.
[0020]
In addition, a level sensor 28 is provided in the hopper 4, and the level sensor 28 detects the level of the fine powder raw material in the hopper, thereby managing the transportation capacity.
[0021]
As shown in FIGS. 3 and 4, the screen unit 10 includes a perforated plate-like curved wall 12a having substantially the same radius of curvature as the inner wall surface 2b of the barrel 2, and a surface facing the curved wall 12a is open. A box-shaped receiving member 12, a screen 11 having a shape covering the curved wall 12a of the receiving member 12 and having a mesh smaller than the average particle diameter of the fine powder raw material, the screen 11 being in close contact with the curved wall 12a and a vent channel And a presser member 13 having a grid-like presser plate 13b.
[0022]
The pressing member 13 includes a shape that can be removably inserted into the receiving member 12, and an outer frame 13 a that has an open opposite surface, and a lattice-shaped pressing plate 13 b that is integrally provided in the outer frame 13 a. Thus, the tip 13c of the pressing plate 13b that contacts the screen 11 is curved in the same manner as the curved wall 12a so that the screen 11 can be held in close contact with the curved wall 12a.
[0023]
In the present embodiment, when the hook-shaped portion 12 c is provided at the open edge of the receiving member 12, the hook-shaped portion 13 d is also provided in the holding member 13, and the holding member 13 is inserted into the holding member 12. The ridges 12c and 13d are overlapped with each other, and both the ridges 12c and 13d are detachably fixed using detachable fixing means such as screws (not shown). Therefore, the screen 11 can be replaced freely, and when the screen 11 is damaged, it can be replaced with a new screen 11.
[0024]
Since the screen unit 10 is configured as described above, the screen unit 10 is mounted in the vent port 8 so that the perforated plate-like curved wall 12a of the receiving member 12 is substantially flush with the inner wall surface 2b of the barrel 2. Then, the inner wall surface side opening of the barrel 2 of the vent port 8 is covered with the screen 11. As a result, the fine powder raw material in the barrel 2 does not pass, but mixed air and gas pass and flow into the forced exhaust chamber 20.
[0025]
If the gap between the perforated plate-shaped curved wall 12a and the flight outer peripheral surface of the screw 3 is set to 1 mm or less, the self-cleaning property of the curved wall 12a is improved.
[0026]
Then, operation | movement of the fine powder raw material supply apparatus by this Embodiment is demonstrated.
[0027]
During normal operation, the air supply valve 23 of each forced exhaust chamber 20 is closed and the exhaust valve 21 is opened to allow the exhaust duct 22 and the forced exhaust chamber 20 to communicate with each other, and is connected to the other end of the exhaust duct 22. Then, the forced exhaust chamber 20 is depressurized to a forced exhaust state.
[0028]
The pulverized raw material supplied to the hopper 4 enters the barrel 2 after a part of the air mixed from the gas vent 7 provided in the hopper 4 is forcibly exhausted, and is rotated by the two rotating screws 3. It is conveyed toward the discharge port 2a.
[0029]
When the fine powder raw material enters the barrel 2 from the hopper 4, the air in the hopper 4 is mixed and mixed into the fine powder raw material. The air mixed in the fine powder raw material of the screen unit 10 attached to each vent port 8. It passes through the mesh of the screen 11 and flows into the forced exhaust chamber 20 as indicated by the arrow, and is forcedly exhausted through the exhaust duct 22.
[0030]
As a result, the fine powder raw material conveyed in the barrel 2 toward the discharge port 2a is prevented from being reduced in bulk density due to air mixing, and the fine powder raw material transport capability of the fine powder raw material supply apparatus 1 is not reduced. A certain amount of fine raw material is stably supplied from the fine raw material supply port 44 of the type extruder 41.
[0031]
When the screen 11 is clogged, the exhaust valve 21 is closed and the air supply valve 23 is opened so that the air supply duct 24 and the forced exhaust chamber 20 are in communication with each other. Compressed air or inert gas is supplied instantaneously (pulse supply) into the forced exhaust chamber 20. Pressurized air or inert gas instantaneously supplied (pulsed) into the forced exhaust chamber 20 flows backward through the screen unit 10 and blows away fine powder material clogged in the screen 11 toward the barrel 2. That is, the screen is clogged by reverse cleaning.
[0032]
Needless to say, this reverse cleaning can be performed for each screen unit 10 of each vent port 8.
[0033]
Next, another embodiment of the fine powder raw material supply apparatus according to the present invention will be described. As shown in FIG. 5, the fine powder raw material supply apparatus 31 according to the present embodiment is provided with two vent ports 8 opposed to both side walls of the barrel 2 and two vent ports on the illustrated upper wall of the barrel 2. 8 and the barrel outer wall side opening of each vent port 8 communicates with the forced exhaust chamber 20. Other than this, since it is the same as the fine powder raw material supply apparatus according to the above-described embodiment, the description thereof is omitted.
[0034]
In each of the embodiments described above, the barrel 2 having two meshing screws is shown. However, the present invention is not limited to this, and the barrel 2 has one screw. Needless to say, the present invention can be applied to one having two non-meshing screws in the barrel 2.
[0035]
Further, the number of vent ports is not limited to two or four shown in the above-described embodiments, but can be changed to three or five or more as necessary.
[0036]
【The invention's effect】
Since this invention is comprised as mentioned above, there exists an effect as described below.
[0037]
In order to forcibly exhaust air or gas mixed in the fine powder raw material through a screen having a mesh smaller than the average particle diameter of the fine powder raw material of the screen unit installed in the vent port provided in the barrel, the bulk of the fine raw material in the barrel A decrease in density is prevented and a high transportation capacity can be maintained. As a result, downsizing is possible, and the fine powder raw material can be stably supplied to an extruder that mixes and extrudes the fine powder raw material with the polymer.
Further, since the pressing member is detachable in the receiving member, the screen can be exchanged.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of a fine powder raw material supply apparatus according to an embodiment.
FIG. 2 is a schematic cross-sectional view taken along the line AA of FIG.
3 is a schematic perspective view of the screen unit in the fine powder raw material supply apparatus shown in FIG.
4 is an exploded perspective view schematically showing the screen unit shown in FIG. 3. FIG.
FIG. 5 is an explanatory view of a fine raw material supply apparatus according to another embodiment.
FIG. 6 is an explanatory view showing an example of a conventional fine powder raw material supply apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1, 31 Fine powder raw material supply apparatus 2 Barrel 3 Screw 4 Hopper 5 Rotation drive mechanism 6 Cooling jacket 7 Degassing port 8 Vent port 10 Screen unit 11 Screen 12 Receiving member 12a Curved wall 12b Hole 12c Gutter-shaped portion 13 Pressing member 13a Outside Frame 13b Presser plate 13c Tip 20 Forced exhaust chamber 21 Exhaust valve 22 Exhaust duct 23 Exhaust duct 23 Inlet valve 24 Inlet duct 25, 27 Pressure gauge 26 Peep window 28 Level sensor 41 Extruder 42 Heating cylinder 43 Screw 44 Fine powder material Supply port

Claims (4)

A fine raw material supply device (1, 31) for supplying the fine raw material to an extruder (41) for mixing and extruding a fine raw material having a small bulk density to a polymer,
The fine powder raw material supply device has a discharge port (2a) connected to a fine powder raw material supply port (44) provided on a side wall of a heating cylinder of the extruder at one end and a hopper (4) at the other end side. A barrel (2), a screw (3) rotatably disposed in the barrel, a rotation drive mechanism (5) for rotating the screw, and an outer wall of the barrel between the hopper and the discharge port; at least two vent ports provided through the inner wall surface from the wall (8), the vent port of the barrel outer wall side opening communicated with the forced ventilation chamber (20), is attached to the vent in the opening Screen unit (10),
The screen unit includes a perforated plate-shaped curved wall (12a) that is substantially flush with the inner wall surface of the barrel, a box-shaped receiving member (12) having an open surface facing the curved wall, and the curved wall. A screen (11) having a mesh smaller than the average particle size of the fine powder raw material covering the grid, and a grid-like presser plate (13b) that closely contacts the curved wall of the receiving member and forms a vent channel A fine powder raw material supply device comprising a holding member (13) having a holding member. The fine powder raw material supply apparatus according to claim 1, wherein a cooling jacket (6) for flowing a cooling medium is provided in the wall of the barrel (2). One end of an air supply duct (24) is connected to the forced exhaust chamber (20) via an air supply valve (23), and pressurized air or inert gas is instantaneously supplied through the air supply duct. The fine powder raw material supply apparatus according to claim 1 or 2, wherein the fine powder raw material supply apparatus is configured to supply the screen (11) for back washing. The fine powder raw material supply device according to any one of claims 1 to 3, wherein a pressure gauge (25) for detecting an internal pressure is attached to the forced exhaust chamber (20).

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