CN-121986018-A - Drying device for synthetic resin forming material

Abstract

The purpose is to provide a drying device for synthetic resin molding material, which can effectively utilize heat energy and can dry in a shorter time in a temperature range where the synthetic resin molding material such as resin particles is not easy to change physical properties. The drying device (1) comprises a drying hopper (2), generating units (8, 7A) for generating drying air for drying the synthetic resin molding material in the drying hopper (2), a drying air supply path (L1) for supplying the drying air to the drying hopper (2), an exhaust air discharge path (L2) for discharging the drying air for drying the synthetic resin molding material in the drying hopper (2) from the drying hopper (2), and an exhaust air supply path (L7) for supplying a part of the exhaust air flowing in the exhaust air flow path (L2) to the drying hopper (2). The drying hopper (2) guides the drying air from the drying air supply path (L1) to the lower side, and guides the exhaust air from the exhaust air supply path (L7) to the upper side.

Inventors

• KIM WON JIN
• Changgang Kangxing

Assignees

• 株式会社大阪冷研

Dates

Publication Date

20260505

Application Date

20240610

Priority Date

20230919

Claims (3)

1. 1. A drying device is provided with: A drying hopper for accommodating the synthetic resin molding material introduced from the upper part and discharging the synthetic resin material from the lower part; A generation unit that generates drying air for drying the synthetic resin molding material in the drying hopper; a drying air supply path for supplying the drying air to the drying hopper; An exhaust air discharge path for discharging, from the drying hopper, drying air after drying the synthetic resin molding material in the drying hopper; An exhaust air supply path for supplying a part of the exhaust air flowing in the exhaust air flow path to the drying hopper, and A heater provided in the exhaust air discharge path and configured to heat the exhaust air supplied to the drying hopper; A drying air introduction part for introducing the drying air from the drying air supply path is provided at a lower part of the drying hopper, and an exhaust air introduction part for introducing the exhaust air from the exhaust air supply path is provided at an upper part of the drying hopper, In the drying hopper, the exhaust air introduction portion is located above the drying air introduction portion.
2. 2. The drying apparatus according to claim 1, wherein the generating section includes a dehumidifying device that generates low dew point air, and a heater that heats the low dew point air to become the drying air.
3. 3. The drying apparatus according to claim 1, wherein the temperature of the drying air supplied to the drying hopper is 120 ℃ to 130 ℃.

Description

Drying device for synthetic resin forming material Technical Field The present disclosure relates to a drying apparatus for removing moisture from synthetic resin molding materials such as resin particles. Background The synthetic resin molding material is usually supplied to a resin molding machine such as an injection molding machine in a state of being processed into pellets. If the resin particles are in a state containing a large amount of moisture, the resin particles are hydrolyzed during melt kneading, and the strength, impact resistance and the like of the molded article are lowered, which significantly lowers the quality of the molded article. In addition, appearance defects of the molded article are also caused. Therefore, the resin pellets are supplied to an injection molding machine or the like after moisture is removed. As means for removing moisture in the resin pellets, for example, a drying apparatus is known which supplies high-temperature and low-dew-point drying air to a drying hopper containing the resin pellets, and brings the drying air into contact with the resin pellets in the drying hopper. In this drying apparatus, the resin particles in the drying hopper are heated by the drying air, so that moisture adhering to the surfaces of the resin particles and moisture contained in the interior are vaporized. Then, the vaporized moisture is carried away by the dry air, thereby removing the moisture from the resin particles (for example, see patent document 1). Fig. 5 shows a schematic configuration of a conventional example of the above-described drying apparatus. The low dew point air is heated to a high temperature in the heater 101 to generate dry air, and the dry air is supplied to the drying hopper 100. The resin pellets are fed from the hopper loader 102 to the drying hopper 100. The resin particles in the drying hopper 100 are heated by the drying air and dried. The solenoid valve 103 is opened, whereby the dried resin pellets are discharged from the drying hopper 100 and supplied to the resin molding machine 105 through the transfer pipe 104. The drying air used for drying the resin pellets in the drying hopper 100 is cooled by the heat of the drying air taken away by the resin pellets, and is discharged from the drying hopper 100 after the humidity is increased by the removal of the moisture from the resin pellets. The dry air (exhaust air) discharged from the drying hopper 100 is removed of foreign matter contained in the exhaust air by the dust collecting device 107, cooled by the cooler 108, compressed by the blower 109, cooled again by the cooler 110, and then supplied to the dehumidifier 106. Then, the discharged air is dehumidified by the dehumidifying apparatus 106 to be low dew point air, and is used again as the drying air for drying the resin particles in the hopper 100. Patent document 1 Japanese examined patent publication No. 7-19770 Disclosure of Invention First, the technical problem to be solved The coolers 108, 110 for cooling the exhaust air typically employ water cooled coolers. The water-cooled cooler can efficiently cool the exhaust air by using the cooling water, but the cooling water, which recovers the heat energy of the exhaust air along with the cooling of the exhaust air, is cooled in the cooling tower. Therefore, although the exhaust air discharged from the drying hopper 100 has a high temperature and has heat energy, the heat energy of the exhaust air cannot be effectively utilized in the conventional drying apparatus. Further, since the drying time is shorter as the temperature of the drying air is higher and the temperature of the dried resin particles is also higher for drying the resin particles, the dried resin particles can be efficiently supplied to a resin molding machine such as an injection molding machine at a high temperature. However, when the temperature of the dry air is increased, the temperature of the resin particles is also increased, and the physical properties of the resin particles are easily changed by decomposition (hydrolysis, oxidative decomposition, thermal decomposition, etc.) or degradation. Therefore, if some abnormality occurs in the drying device during the drying of the resin particles, the resin particles remain in the drying hopper at a high temperature for more than a predetermined drying time, there is a possibility that the physical properties of the resin particles may be changed. On the other hand, if the temperature of the dry air is low, there is a problem in that the drying time of the resin particles becomes long. The present disclosure has been made in view of the above circumstances, and an object thereof is to provide a drying apparatus for a synthetic resin molding material, which can effectively utilize heat energy and can dry the synthetic resin molding material in a shorter time in a temperature range in which a change in physical properties of the synthetic resin molding material such as resin partic