JP2007190767A - Exhaust method of high-density volume-reducing molding machine of waste plastic - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exhaust method of a high-density volume-reducing molding machine of a waste plastic capable of efficiently exhausting the gas in the high-density volume-reducing molding machine and capable of efficiently sucking the gas in a molten material to enhance the specific gravity of a pellet. <P>SOLUTION: In the exhaust method of the high-density volume-reducing molding machine of the waste plastic, charged fluff is compressed and melted while moved by a screw 1b and the molten matter is extruded to manufacture pellets. Exhaustion is performed in a first stage and a second stage and, in the first stage, evaporated steam is exhausted from the first vent 4 arranged to a region where a part of the fluff charged in the high-density volume-reducing molding machine of the waste plastic begins to melt while, in the second stage, the volatile component of the molten matter is sucked from the second vent 5, which is arranged to a region where the melting of a raw material advances, by a vacuum pump. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for exhausting a waste plastic high-density volume reducing machine that compresses and kneads waste plastic to produce pellets.

  In equipment that recycles waste plastic discharged from local governments by the Containers and Packaging Recycling Law as raw materials for coke, the waste plastic becomes a fluff with components and shapes suitable for pelletization by rough crushing, sorting, and secondary crushing. The volume is reduced to produce pellets. The exhaust gas generated in the volume reduction molding machine is extracted using a water ring vacuum pump and sent to a dust collector.

  FIG. 4 is a schematic view showing an outline of a conventional waste plastic volume reduction molding machine.

  The fluff supplied to the high-density volume reduction molding machine 1 in which the rotating screw 1b is disposed in the cylinder 1a is melted and kneaded by heating by the heater and the frictional heat of the fluff while moving by the rotation of the screw 1b. Extruded from the die 1c. The waste plastic volume reduction molding machine is provided with a vent, and water vapor and volatile matter generated in the volume reduction molding machine are extracted from the vent by a vacuum pump. The extruded kneaded product is cut into pellets by the rotary blade 2 (see Patent Document 1).

In the high-density volume reduction molding machine 1, the temperature is raised to 180 to 220 ° C. by the heating by the heater and the frictional heat of the fluff itself, so that the specific gravity of the single pellet is increased. In high-density volume reduction molding, volume reduction waste does not occur, so that the handling can be improved, and the coke production and coke quality can be improved.
Japanese Patent Laid-Open No. 6-293021

  In a conventional high-density volume-reduction molding machine, if the gas such as air entrained by the fluff, water vapor generated by evaporation of attached water, volatile matter generated from the melt is not extracted during the volume reduction process, the gas will be pelletized. It remains inside, expands, and the cavity becomes larger, reducing the specific gravity. For this reason, gas such as water vapor and volatile matter is collectively extracted from a single vent from the inside of the high-density volume reduction molding machine using a vacuum pump. The gas present inside the object could not be sufficiently sucked. Therefore, the specific gravity of the pellet may not be high. Further, not only the fluff is sucked and scattered before melting, but there are cases where stable exhaust suction cannot be performed due to the influence of the dust collection line in the subsequent process.

  Therefore, the present invention efficiently discharges the gas in the high-density volume reduction molding machine and efficiently sucks the gas inside the melt, thereby improving the specific gravity of the waste plastic. A method for exhausting the aircraft is provided.

  The present invention relates to an exhaust method of a waste plastic high-density volume molding machine that compresses and melts a thrown fluff while moving it with a rotating screw, and extrudes the melt to produce pellets. The steam evaporated from the fluff is exhausted from a first vent disposed in a region where a part of the fluff charged into the waste plastic high-density volume reduction molding machine in the first step begins to melt, It is characterized in that the volatile matter of the melt is sucked by a vacuum pump from the second vent arranged in the region where the melting of the raw material has progressed in the second stage.

  The exhaust from the first vent in the first stage is (1) sucked with a blower through a trap, (2) the exhaust from the first vent is once released to the atmosphere, and then sucked with a blower through a hood. (3) The gas sucked by the blower is once released to the atmosphere, and then sucked by a dust collection line blower via a hood. (4) The exhaust from the first vent is decelerated by a reduction tower and then sucked by a blower. be able to.

  The present invention performs the exhaust of the high-density volume reduction molding machine in two stages. First, in the first stage, the vapor that evaporates in the first vent disposed in the region where a part of the raw material starts to melt is spontaneously generated. By exhausting, stable exhaust can be achieved without being affected by fluctuations in the dust collection line in the subsequent process while suppressing scattering of fluff.

  Next, in the second stage, the pellets are obtained by actively sucking the gas present in the melt by sucking with a vacuum pump from the second vent disposed in the region where the melting of the raw material has proceeded. The specific gravity can be improved.

  In the second stage, the volatile component of the melt is mainly exhausted. In the second stage, stable exhaust suction is possible without using a vacuum pump having a large capacity and without being affected by the dust collection line. .

  FIG. 1 is a schematic view of a waste plastic high-density molding machine used in the degassing method of the present invention, and FIG. 2 is a view showing a suction line of a second vent.

  The fluff supplied to the high-density volume reduction molding machine 1 in which the rotating screw 1b is disposed in the cylinder 1a is melted and kneaded by heating with the heater and the frictional heat of the raw material while moving by the rotation of the screw 1b. Extruded from the die 1c. The extruded kneaded material is cut into the pellets 3 by the rotary blade 2.

  In the present invention, the gas generated in the high-density volume reduction molding machine is exhausted in two stages. First, in the first stage, water vapor generated by evaporation of water adhering to the raw material is discharged from the first vent 4 disposed in a region where a part of the raw material begins to melt, and the exhaust gas is sent to a dust collector.

  Next, in the second stage, exhaust gas is sucked with a vacuum pump from the second vent 5 disposed in the region where the melting of the raw material has further progressed, and the gas existing inside the melt is actively sucked, Perform deaeration to improve specific gravity. As shown in FIG. 2, the exhaust from the second vent 5 is sucked by the vacuum pump 7 through the trap 6.

  FIG. 3 is a diagram showing an exhaust stroke in the first stage of the present invention.

  In FIG. 3A, the first vent 4 is disposed in a region of the raw material of the high-density volume reduction molding machine 1 where a part of the raw material starts to melt, and is generated by evaporation of water adhering to the raw material from the first vent 4. The steam is exhausted, once released into the atmosphere, and then sucked from the hood 9 by the blower 8 provided in the dust collection pipe and sent to the dust collector through the trap 6. If the generation of water vapor is not constant, the blower 8 sucks the exhaust gas and the air by releasing the exhaust gas to the atmosphere. Therefore, even if the exhaust gas amount fluctuates, a constant amount of gas can be sucked. The exhaust gas can be processed stably without being affected by the fluctuation of the dust line.

  If the moisture adhering to the raw material is almost constant and the generation of water vapor is constant, the exhaust from the first vent is collected without opening the exhaust to the atmosphere as shown in FIG. You may suck | suck with the blow nozzle 8 provided in piping, and may send to a dust collector through dust collection piping.

  Further, as shown in FIG. 3C, the gas sucked by the blower 8 is once released to the atmosphere so as not to be affected by the fluctuation of the dust collection line, and then the blower ( (Not shown) may be used.

  Moreover, as shown in FIG.3 (d), the scattering of a fluff can be suppressed by decelerating the exhaust_gas | exhaustion from the 1st vent 4 with the reduction tower 12. FIG.

<Example>
A fluff was introduced into a high-density volume reduction molding machine at 4.2 t / h and exhausted in two stages. The first vent was evacuated by opening to the atmosphere shown in FIG. 3A, and suctioned at a melting temperature of 190 to 200 ° C., a gas temperature of the second vent of 150 ° C., and a vacuum pump suction pressure of 100 Torr. The specific gravity of the pellet was 0.9.

<Conventional technology>
The first vent was closed, and suction was performed with a vacuum pump only from the second vent under the conditions of Example 1. The specific gravity of the pellet was 0.7.

  By exhausting in two stages according to the present invention, the specific gravity of the pellet could be improved as compared with the case where the specific gravity of the pellet was sucked only by the second vent. In addition, scattering of fluff was suppressed and stable operation was possible.

It is the schematic of the waste plastics high density molding machine used for the deaeration method of this invention. It is a figure which shows the suction line of a 2nd vent. It is a figure which shows the Example of the exhaust method of a 1st vent. It is the schematic of the conventional waste plastics high density molding machine.

Explanation of symbols

1: High density volume reduction molding machine 1a: Cylinder 1b: Screw 1c: Die
2: Rotating blade 3: Pellet 4: First vent 5: Second vent
6: Trap 7: Vacuum pump 8: Blower 9: Hood 10: Hood 11: Blower 12: Reduction tower

Claims (5)

  In the exhaust method of the waste plastic high-density volume molding machine that compresses and melts the introduced fluff while moving it with a rotating screw and extrudes the melt to produce pellets, exhausting is performed in the first stage and the second stage, In the first stage, the water vapor evaporated from the fluff is exhausted from a first vent disposed in a region where a part of the fluff charged into the waste plastic high-density volume reduction molding machine starts to melt, and then in the second stage. A method for exhausting a waste plastic high-density reduction molding machine, characterized in that a volatile component of a melt is sucked by a vacuum pump from a second vent disposed in a region where melting of the raw material has proceeded.   The exhaust method of the waste plastic high-density volume reduction machine according to claim 1, wherein the exhaust from the first vent is sucked by a blower through a trap.   3. The exhaust method of a waste plastic high-density volume molding machine according to claim 2, wherein the exhaust from the first vent is once released to the atmosphere and then sucked by a blower through a hood.   3. The exhaust method of a waste plastic high-density reduction molding machine according to claim 2, wherein the gas sucked by the blower is once released to the atmosphere and then sucked by a blower of a dust collection line through a hood.   The exhaust method for a waste plastic high-density volume molding machine according to any one of claims 1 to 4, wherein the exhaust from the first vent is decelerated by a reduction tower and then sucked by a blower.

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