JPH02127006A - Hopper drier - Google Patents

Abstract

PURPOSE:To shorten a time for drying by a method wherein an inner tube and an outer tube both of which are provided with a number of hot-air supply holes are provided in the outer circumference of a heat source located in the center and a resin material is heated between the two tubes. CONSTITUTION:In the center of a tubular main body A, a sheath heater 2 is suspended from a support 1 wherein an air vent 1a is made. In the outer periphery of a heat conducting tube 3, an inner tube 4 and an outer tube 6 both of which are provided with a number of hot-air supply holes 4a and 6a respectively are disposed concentrically. When a resin material is sent to a collector B through a material supply valve 15 by a pneumatic transporter or the like, it is released from a material supply port 7c of the main body A of a hopper and packed in a gap between the inner tube 4 and the outer tube 6 inside the main body A. Meanwhile, hot air heated by the heater 2 of a heat source is released from the small holes 4a of the inner tube into the small holes 6a through the resin material. Ventilation resistance is small and the hot air is easy to be sent.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a hopper dryer used for preheating and drying resin pellets and the like.

[Prior Art] Conventionally, when feeding resin materials such as resin pellets into a molding machine, a method has been adopted in which hot air is blown to preheat the resin material to promote softening and melting, and at the same time to dry it.

However, with this method of drying resin materials, the resin pellets are stored in the hopper and then dried by blowing hot air, which requires a large hopper and takes up space. There was a problem that the drying device was large and the entire drying device became large.

In addition, since the resin pellets are stored in the hopper and dried by blowing hot air from the bottom of the hopper, it takes a long time to dry, and the drying process is not carried out as usual. There were also problems such as variations in drying depending on the vertical position of the resin material.

In order to solve this problem, a hopper dryer with a double height structure has been proposed.

FIG. 4 shows a conventional double-tube structure hopper dryer, in which the main body 100 has a large number of small holes 1 for suctioning hot air.
An inner wall 102 having a large number of small holes 102a for hot air suction is arranged concentrically within an outer wall 101 having holes 01a, and the tip of the inner wall 102 is connected to an air suction source such as a vacuum pump. A band heater 1 is installed around the outer wall 101.
03 is provided. In this hopper dryer, the resin material 106 stored in the hopper 105 provided on the upper side is fed into the gap between the outer wall lO1 and the inner wall 102, and hot air is supplied by the band heater 103 while the resin material 106 is passed through the gap. I try to dry it.

However, in such a hopper dryer,
Since the band heater 103 is provided around the outer periphery of the outer wall 101, if the entire device is to be made compact, it is necessary to
The gap between 01 and the inner wall 102 also became smaller, resulting in a disadvantage that the storage tank for the resin pellets became smaller.

Furthermore, in such a structure, the band heater 103
Since the structure is located on the outside, it is difficult to disassemble and clean, especially when the resin material is frequently replaced.

[Problems to be Solved by the Invention] The present invention was developed to solve the above problems, and provides a hopper dryer that reduces the size of the entire i-chamber and can dry in a short time without uneven drying. The purpose is to

[Means for Solving the Problems] The hopper dryer of the present invention proposed to achieve the above object has a heat source placed in the center of the main body, and a large number of hot air supply holes bored around the outside of the heat source. It has a structure in which an inner cylinder is installed vertically, and an outer cylinder with many hot air exhaust holes is installed concentrically around the outer circumference of the inner cylinder, and drying gas is placed inside the inner cylinder. I'm trying to get it delivered.

[Function] According to the hopper dryer of the present invention, an inner cylinder provided with a large number of hot air supply holes provided around the outer periphery of a central heat source;
A donut-shaped gap sandwiched between the inner cylinder and an outer cylinder provided with a large number of hot air discharge holes arranged around the outer periphery forms a material storage tank.

Therefore, if drying gas is supplied into the inner cylinder, the drying gas will be heated by the heat source and will heat the resin material tank when it is released from the hot air supply hole in the inner cylinder to the hot air discharge hole in the outer cylinder. , the ventilation area is wide, the ventilation resistance is reduced,
The volume of hot air also increases.

Therefore, the temperature of the resin material increases quickly, there is less uneven drying, and the drying time is also significantly shortened.

[Example] The present invention will now be described in detail with reference to the accompanying drawings.

FIG. 1 is a vertical cross-section showing the hopper dryer according to the present invention in use, FIG. 2 is a perspective view of the hopper dryer main body partially cut away, and FIG. 3 is an external view of the main body.

As shown in FIGS. 1 and 2, this hopper dryer has a double wall structure 8a for insulating the outer wall.

At the center of the cylindrical body 8b, three sheathed heaters 2 are suspended and supported on a support plate 1 having a ventilation hole 1a.
Around the outer periphery, cylindrical heat conduction cylinders 3 are provided at appropriate intervals to surround the heater 2 and constitute a heat source.

An inner cylinder 4 having a large number of hot air supply holes 4a and a tapered opening 4b at the tip is disposed on the outer periphery of the heat conduction cylinder 3.
Around the outer periphery of the inner cylinder 4, an outer W6 having a large number of hot air supply holes 6a is arranged concentrically.

The upper casing 7A of the hopper main body A has an air passage 7a formed from a blower 9 provided on the outside of the main body toward the heat conduction cylinder 3, and upward from the gap between the inner cylinder 4 and the outer cylinder 6. has a material supply path 7b. Moreover, between the outer rR6 and the inner wall 8a of the double wall 8, there is provided an exhaust passage 7g that communicates upward.

The above support plate l, inner W4. The outer rR6 is fixed to the upper casing 7A of the main body A, and the support plate 1 is connected to the blower 9.
The inner cylinder 4 is fixed to the opening of the air passage 7a to which the inner cylinder 4 is connected, and the inner cylinder 4 extends downward from the air passage 7a whose opening is closed by the support plate 1. Further, the outer cylinder 6 is connected to the material supply path 7b and extends downward.

The hopper main body A having such a structure has a tapered lower end, and is provided with a lower casing 7B at its lowest portion, which opens a material discharge lower e connected to a material supply port of a molding machine.

In addition, 10 is a control box attached to the outer peripheral wall of the hopper main body part A.

In the hopper dryer characterized by the above structure, as shown in FIG. 3, the collector B is connected to the material supply lower C provided at the upper part of the hopper main body A. The collector B is provided to temporarily collect the resin material before supplying the resin material to the hopper main body A, and to keep the material in the hopper main body A constantly full.

The collector B has an outer wall 12 made of a material that allows the interior to be seen through.
13 is an air vent for discharging transport gas such as air supplied together with the resin material to the collector B, and below it is a powder collector that separates and collects the resin material powder. 14 are provided. A material supplying vibrator 15 is connected to the upper part of the collector B.

In a hopper dryer with such a structure, when the resin material is sent to the collector B via the material supply pipe 15 by a pneumatic conveyor or the like, it is discharged from the material supply lower C of the hopper main body A and flows inside the main body. The gap between the inner 14 and outer 16 of A is filled.

On the other hand, heat conduction 111+3 from Proa 9 via air passage 7a
The air sent into the interior is heated by the heater 2 as a heat source and becomes hot air, which is then radially released from the small holes 6a of the outer cylinder 6 through the many small holes 4a of the inside 114 through gaps filled with resin material. and is discharged to the outside from the exhaust lower d or returned to the lower side.

In the hopper dryer of the present invention, the resin material passed through the hot air is heated and dried, but in this case, the hot air is passed radially from the center layer toward the outer layer of the donut-shaped resin layer. Therefore, compared to the conventional structure in which hot air flows from the bottom layer of the resin layer to the top layer,
There is little ventilation resistance, and hot air can easily pass through. Therefore, the temperature of the resin material increases quickly and the drying time is significantly shortened.

[Effects of the Invention] The hopper dryer of the present invention has the following effects due to its structural features.

The storage tank that stores the resin material is formed in a donut shape, and the hot air for drying is discharged radially from the center layer toward the outer layer of the resin tank, so the ventilation area is wide, the ventilation resistance is reduced, and the amount of hot air is increased. Therefore, the drying time is dramatically shortened.

The structure of the hopper dryer is centered around the heat source, and the inner and outer cylinders can be removed by removing the top, making it easy to disassemble and clean, which is useful when changing materials frequently. be.

Since the heat source is placed in the center, a larger amount of resin material can be stored than in a case where the heat source is placed around the outside.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-section of the main part showing the hopper dryer of the present invention in use. FIG. 2 is a partially cutaway perspective view of the hopper main body. Figure 3 is an explanatory diagram of the appearance of the hopper dryer. FIG. 4 is a structural explanatory diagram of a conventional two-type cylindrical hopper dryer. [Explanation of symbols] A... Hopper dryer body 2... Heat source 4... Inner tube 4a... Hot air supply hole 6... Outer tube 6aΦ... Hot air discharge hole Patent applicant Matsui Seisakusho Co., Ltd.

Claims (1)

[Claims] 1) A heat source is placed in the center of the main body, an inner cylinder with many hot air supply holes is installed vertically around the outside of this heat source, and many hot air exhaust holes are formed around the outside of this inner cylinder. A hopper dryer characterized in that the outer cylinder is arranged concentrically to form a donut-shaped material storage tank, and a drying gas is supplied to a heat source within the inner cylinder.