JPH0592426A - Particle feed hopper for pre-expander - Google Patents

Abstract

PURPOSE:To perform efficient drying by obtaining a particle feed hopper fitted with a dryer constituted so that foamable resin particles are pre-expanded to be received in a hopper part and the pre-expanded particles are sucked up by a particle feed blower to be blown in the drying tower provided to the upper surface of the hopper part along with hot air and returned to the hopper part to be circulated and dried to be fed to a next process. CONSTITUTION:A hopper part 3 is provided to the feed-out port 2 of a pre-expander 1 and pre-expanded resin particles with low expanding magnification of about 3-10 times are received in the hopper part 3. A lid 5 is provided to the open upper surface of the hopper part 3 and a drying tower 6 is erected on the lid 5. The lid 5 and the drying tower 6 are formed of an air permeable metal net not permitting the resin particles to pass. The resin particles are sucked from the bottom part of the hopper part 3 by a particle feed blower 13 to be struck by the internal blades of the blower 13 and blown up into the drying tower 6 from the inner pipe 10 of a blowoff nozzle 8 composed of a double pipe and hot air is blown up from an outer pipe 11. Evaporated moisture is discharged from the side surface of the drying tower along with hot air and the resin particles return to the hopper part 3. This operation is repeated and a damper 15 is changed over after drying and the dried resin particles are sent to an ageing silo by the particle feed blower 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a granulating hopper for a pre-expanding machine, and more specifically, a pre-expanding machine for pre-expanding expandable resin particles at a low expansion ratio of about 3 to 10 times (hereinafter referred to as "low expansion foaming" (Hereinafter abbreviated as “.”).

[0002]

2. Description of the Related Art Conventionally, the following three types of methods have been employed to dry pre-expanded particles obtained by heating and expanding foamable resin particles with steam in a pre-expanding machine. The first method is to blow cold air, warm air, or hot air into the pre-foaming machine to dry it after the completion of pre-foaming. In the second method, after the drying in the first method, the pre-expanded particles are pressure-fed to the aged silo with hot air or hot air to further dry the particles. The third method is that after pre-foaming is completed,
It is discharged without being dried in the pre-foaming machine, and the discharged pre-foamed particles are stored in a storage tank or a tunnel-shaped container and blown with hot air to dry.

[0003]

However, according to the first method of the above-mentioned conventional methods, the time required for one cycle of the prefoaming machine (feeding of raw material → preliminary foaming → drying → discharging) becomes long. , The processing capacity of the pre-foaming machine decreases. Further, according to the second method, when the pre-expanded particles have a low expansion ratio, the specific gravity of the pre-expanded particles is large, and therefore the particles cannot be fed by pressure feeding. Further, according to the third method, since hot air is blown into the pre-expanded particles in the stored state, it takes a long time to dry,
Moreover, when the pre-expanded particles have a low expansion ratio and a large specific gravity, it takes a longer time, and the installation place of the drying equipment becomes wider.

The present invention is an improvement over the conventional grain feeding hopper,
The purpose is to eliminate the above-mentioned problems.

[0005]

In order to achieve the above object, a granulating hopper for a pre-expanding machine of the present invention comprises a pre-expanding particle on an open upper surface of a hopper portion provided at a pre-expanding particle discharge port of the pre-expanding machine. A lid that does not pass through, a standing cylindrical drying tower that has air permeability but does not allow the pre-expanded particles to pass through is installed on the lid, and a granulation blower is connected to the outlet of the bottom of the hopper. A blow-out nozzle having an inner-outer double-pipe structure is attached to the side wall of the hopper portion toward the drying tower, and the inner pipe of the blow-out nozzle is connected to the discharge port side of the granulating blower through a switching damper, and A hot air generator is connected to the outer tube of the blowout nozzle.

[0006]

The granulating hopper having the above construction is attached to the low-expansion pre-expanding machine, and temporarily stores the low-expansion pre-expanded particles discharged from the pre-expanding machine. Grain blower,
The pre-expanded particles are sucked from the outlet at the bottom of the hopper, the pre-expanded particles are beaten by the inner blade, and the pre-expanded particles are sent from the discharge port to the inner tube of the blowout nozzle through the switching damper and blown up toward the drying tower. At that time, since the pre-expanded particles are low-expansion foam,
It won't shatter even if it is hit with the wings. On the other hand, the hot air generator sends hot air for drying to the outer tube of the blowing nozzle,
Blow up towards the drying tower. The pre-expanded particles and hot air blown up from the blowing nozzle are mixed and enter the drying tower,
Hot air dries the pre-expanded particles. As a result, the evaporated water is released into the atmosphere from the wall surface of the drying tower together with the hot air, and the pre-expanded particles fall back to the bottom of the hopper. When the drying cycle is repeated a required number of times and the drying is completed, the switching damper is switched, and the granulation blower transfers the dried pre-expanded particles to the next facility, for example, an aged silo.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. In the particle feeding hopper of this embodiment, as shown in FIG. 1, a hopper portion 3 is provided at a pre-expanded particle discharge port 2 of a low-expansion pre-expanding machine 1. The hopper 3 has a sieving sieve 4 stretched inside, a lid 5 is attached to the open upper surface, a cylindrical drying tower 6 is erected on the lid 5, and a discharge port 7 is provided at the bottom. At the same time, the blowing nozzle 8 is attached to the side wall toward the drying tower 6. The lid 5 and the drying tower 6 are made of wire mesh or the like that has air permeability but does not allow pre-expanded particles to pass through, and the outlet 7 has an air suction port 9 attached with the wire mesh.
Is provided, and the blowout nozzle 8 has an inner-outer double pipe structure including an inner pipe 10 and an outer pipe 11.

Then, a granulation blower 13 is provided in the granulation pipe 12 connected to the outlet 7, and a blowing nozzle 8 is provided on the discharge port 14 side of the granulation blower 13 via a switching damper 15 and a circulation pipe 16.
The inner pipe 10 of is connected. The switching damper 15 is a three-way damper having a “circulation” position where the circulation pipe 16 is brought into conduction with the granulation pipe 12 and a “granulation” position where the circulation pipe 16 is cut off from the granulation pipe 12. Further, a hot air generator 18 is connected to the outer tube 11 of the blowing nozzle 8 via a drying tube 17. The hot air generator 18 sends a blower 20 to the heater 19.
Is connected, and hot air for drying having a temperature of room temperature to a maximum of about 80 ° C. is supplied.

In the granulating hopper having the above construction, the low-expansion pre-expanded particles 21 discharged from the pre-expanded particle discharge port 2 of the pre-expander 1 are sized by the sieve 4 in the hopper section 3 and then once It is stored in the bottom of the hopper unit 3. Subsequently, the particle-sending blower 13 and the hot air generator 18 enter the operating state, and the switching damper 15 is set to the “circulation” position. As a result, the particle-sending blower 13 sucks the pre-expanded particles 21 from the outlet 7 of the hopper 3 through the particle-sending tube 12, hits the pre-expanded particles 21 with the internal blade, and discharges the pre-expanded particles 21 from the discharge port 14. The inner pipe 1 of the blow-out nozzle 8 via the switching damper 15, the switching damper 15, and the circulation pipe 16.
The particles are fed to 0 and blown up toward the drying tower 6. At this time, since the pre-expanded particles 21 are low-expansion foam, they do not break even if they are hit with a blade. On the other hand, the hot air generator 18
Sends the hot air for drying to the outer pipe 11 of the blowing nozzle 8 through the drying pipe 17 and blows it up toward the drying tower 6. The pre-foamed particles 21 blown up from the blow-out nozzle 8 and the hot air are mixed and enter the drying tower 6, and the hot air dries the pre-foamed particles 21. As a result, the evaporated water is released into the atmosphere from the wall surface of the drying tower 6 together with the hot air, and the pre-expanded particles 2
1 drops and returns to the bottom of the hopper 3. When the drying cycle is repeated a required number of times to complete the drying, the switching damper 15
Is switched to the "granulation" position and the hot air generator 1
8 is stopped, and the granulation blower 13 is dried pre-expanded particles 2
1 is sucked from the discharge port 7 of the hopper unit 3 and is fed from the discharge port 14 to the next facility, for example, an aged silo via the switching damper 15 and the grain feeding pipe 12. Since the pre-expanded particles 21 are dried with hot air, curing in the aged silo is promoted.

Incidentally, Table 1 shows the measurement results of the drying time in the granulating hopper of the present invention and the drying time in the conventional method. In this case, in the present invention, expanded styrene beads "Kanepearl HDB" (trade name, manufactured by Kaneka Kagaku Kogyo Co., Ltd.) were pre-expanded to a expansion ratio of 10 times and 5 times by heating steam in a low-expansion pre-expansion machine. Immediately after that, the granules were discharged into a granulating hopper and dried and circulated until the pre-expanded particles had no surface tightness, that is, until the surface water content was about 0.5%, and the drying time was measured.

Further, in the conventional method, after the expanded styrene beads are pre-expanded under the same conditions as described above, the heating steam is stopped, cooling air is blown into the pre-expanding machine to dry the pre-expanded particles, and the surface shrinkage of the pre-expanded particles is suppressed. The drying time until disappearance was measured.

[0012]

[Table 1]

As is clear from Table 1, the drying time in the present invention is shortened to 1/4 or less of the drying time in the conventional method.

[0014]

INDUSTRIAL APPLICABILITY As described above, according to the present invention, the pre-expanded particles are blown up from the blowing nozzle into the drying tower together with the hot air for drying, so that the pre-expanded particles can be dried in an extremely short time. Further, since the drying in the pre-foaming machine is unnecessary, the time required for one cycle of the pre-foaming machine is shortened,
The processing capacity of the pre-foaming machine is improved. Further, since the drying device is provided in the grain feeding hopper, the installation space is small. Further, since the pre-expanded particles are dried by hot air, the curing of the pre-expanded particles in the aging silo is promoted.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a grain feeding hopper showing an embodiment of the present invention.

[Explanation of symbols]

1 Pre-foaming machine 2 Pre-foamed particle discharge port 3 Hopper part 5 Lid body 6 Drying tower 7 Discharge port 8 Outflow nozzle 10 Inner tube 11 Outer tube 13 Grain blower 14 Discharge port 15 Switching damper 18 Hot air generator 21 Pre-foamed particle 21

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location B29K 105: 04

Claims (1)

[Claims] 1. A lid that does not allow pre-expanded particles to pass through is attached to an open upper surface of a hopper portion provided at a pre-expanded particle discharge port of the pre-expanding machine, and the pre-expanded particles do not pass through the cover having air permeability. A cylindrical drying tower is erected, and a grain-blowing blower is connected to the outlet of the bottom of the hopper, and a blow-out nozzle having an inner and outer double pipe structure is attached to the sidewall of the hopper toward the drying tower, A granulating hopper for a pre-foaming machine, in which an inner tube of the blowout nozzle is connected to a discharge port side of the particle feeding blower through a switching damper, and a hot air generator is connected to an outer tube of the blowout nozzle.