JP3305950B2 - Hopper dryer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hopper dryer, and more particularly, to preventing a blocking phenomenon from occurring near a discharge pipe of a hopper when the discharge of a resin material after a drying process in the hopper is stopped. As for the hopper dryer.

[0002]

2. Description of the Related Art Conventionally, as this kind of hopper dryer, for example, a hopper dryer as shown in FIG. 4 has already been proposed. The hopper dryer D includes a hopper 1 that stores a granular material or the like such as pellets to be dried (hereinafter, simply referred to as a resin material),
Hot air supply means 2 attached to the hopper 1;
A diffuser cone 3 provided in the hopper 1, an air supply pipe 4 connecting between the diffuser cone 3 and the hot air supply means 2, and an exhaust gas recovery pipe 5 connecting between the hopper 1 and the hot air supply means 2 And

[0003] The hopper 1 has a cylindrical body 1a,
A conical portion 1 that tapers downwardly as it goes down
b and a central portion of the conical portion 1b,
A discharge pipe 1c for discharging the resin material after being dried from the hopper 1 and a material input port 1f provided in a central portion 1e of an upper portion (top plate) 1d thereof, and an upper portion (top plate) thereof
1d and an air discharge port 1g provided on the side of the material input port 1d.

[0004] Above the material input port 1f of the hopper 1,
For example, a resin material storage hopper 6 in which a resin material to be dried is stored is provided via a material cutting shutter 7. Also, the discharge pipe 1c of the hopper 1
Below, a material transport pipe (not shown) and a material input port (not shown) of a molding machine or the like are connected.

The hot air supply means 2 includes a heating means (not shown) for heating and drying air and the like, and a blowing means (not shown) such as a blower for supplying hot air into the hopper 1. I have. One end 3a of the diffuser cone 3 is connected to an air supply pipe 4 connected to the hot air supply means 2 on the side of the straight body 1a of the hopper 1, and a lower portion 3b thereof.
An opening 3c is provided at the upper central portion near the discharge pipe 1c of the hopper 1 and has a lower portion 3b through which hot air supplied from the hot air supply means 2 is diffused and supplied into the hopper 1. And a plurality of small holes 3d formed in the outer peripheral surface 3e outside the opening 3c.

An exhaust gas recovery pipe 5 is provided so as to connect between an air discharge port 1g provided in an upper portion (top plate) 1d of the hopper 1 and the hot air supply means 2. Then, the hot air generated by the hot air supply means 2 is diffused and supplied into the hopper 1 from the opening 3c of the lower portion 3b of the diffuser cone 3 and the small holes 3d formed on the outer peripheral surface outside the opening 3c. The air is circulated to the hot air supply means 2 through an air discharge port 1g provided in an upper portion (top plate) 1d of the hopper 1 and an exhaust gas recovery pipe 5, and is regenerated into hot air by the hot air supply means 2, and the hopper 1 It is made to circulate inside.

When a predetermined amount of resin material is dried by using the hopper dryer D, first, the material cutting shutter 7 is opened for a predetermined time, and a predetermined amount of resin material stored in the material storage hopper is removed. Housed in hopper 1. Next, the hot air supply means 2 is operated to blow hot air of a predetermined temperature into the resin material accommodated in the hopper 1,
The resin material contained in the hopper 1 is dried.

[0008] The resin material after the drying process is
The material is sequentially supplied from a discharge pipe 1c of the hopper 1 to a material transport pipe (not shown) connected to the discharge pipe 1c or a material input port (not shown) of a molding machine or the like.

[0009]

The above-mentioned conventional hopper dryer D has a discharge pipe 1c of the hopper 1.
Although there is no particular problem when the resin material after the drying process is smoothly supplied to a material transfer pipe (not shown) or a material input port (not shown) of a molding machine or the like, for example,
When replacing the resin molding die, for example, when the supply of the resin material to the material transfer pipe (not shown) or the material inlet (not shown) of the molding machine is temporarily stopped, As shown in FIG. 5, there are many cases in which resin materials such as pellets adhere to each other near the discharge pipe 1c of the hopper 1 to cause a so-called blocking phenomenon.
M represents a resin material such as pellets fixed to each other and formed into a block).

When such a blocking phenomenon occurs,
After that, even when the supply of the resin material to the material transfer pipe (not shown) or the material input port (not shown) of the molding machine or the like is resumed, the dried resin material is discharged from the discharge pipe 1c of the hopper 1. In addition, it cannot be supplied to a material inlet (not shown) such as a material transport pipe (not shown) or a molding machine. For this reason, conventionally,
In FIG. 5, a knocker or the like which can be intermittently driven by an air cylinder or a hydraulic pressure as shown by reference numeral 8 is provided, and a vibration is applied to the hopper 1 to forcibly remove resin material such as pellets from the hopper 1. A device has been devised to drop the material into a material inlet (not shown) such as a transportation pipe (not shown) or a molding machine.

However, once the resin material M such as pellets which are fixed to each other and are blocked in the hopper 1 is formed, even if the hopper 1 is vibrated intermittently by using the knocker 8, the blocked resin Material M does not break,
After being clogged in the discharge pipe 1c, it goes to a material transfer pipe (not shown) or a material input port (not shown) of a molding machine or the like.
The supply of the resin material after the drying process becomes impossible, or the resin material after the drying process is broken into several small blocks. Even if the resin material after the drying treatment can be supplied to the resin material (not shown), the resin material in the form of small blocks is supplied to a material inlet (not shown) of a material transport pipe (not shown) or a molding machine. Suddenly, when the hopper 1 is intermittently vibrated by using the knocker 8, the supply of the resin material after the smooth and smooth drying process is hindered.
The blocked resin material M is broken, and a large amount of the resin material after the drying process is supplied to a material transfer pipe (not shown) or a material input port (not shown) of a molding machine or the like at a time.

For this reason, for example, when the resin molding die is replaced, the supply of the resin material to a material transfer pipe (not shown) or a material inlet (not shown) of a molding machine or the like is temporarily stopped. Even in such a case, there has been a long-felt need for a hopper dryer in which resin materials M such as pellets fixed to each other and blocked in the hopper 1 are not formed. The present invention has been made in order to solve the above-described problems, and even when the discharge of the resin material after the drying treatment in the hopper is stopped, the resin materials are fixed to each other near the discharge pipe of the hopper and are blocked. An object of the present invention is to provide a hopper dryer capable of preventing generation of resin material such as formed pellets.

[0013]

According to a first aspect of the present invention, there is provided a hopper dryer in which hot air generated by hot air supply means attached to a hopper is blown into a resin material to be dried contained in the hopper. In a hopper dryer that dries the resin material contained in the hopper and discharges the dried resin material from a discharge pipe provided at the bottom of the hopper, a material suction port is provided in the discharge pipe. At the same time, a circulation path having a material discharge port at the upper part of the hopper, and in the middle of the circulation path, flows in the circulation path from a material suction port provided at the discharge pipe to a material discharge port provided at the upper part of the hopper. Airflow generating means for generating an airflow, at least when the resin material after the drying process is not discharged from the discharge pipe of the hopper, operates the airflow generating means The resin material that has been dried in the hopper is generated from the material suction port provided in the discharge pipe toward the material discharge port provided in the upper part of the hopper. Part of the
The material was sucked through the material suction port provided in the discharge pipe, and was circulated to the inside of the hopper from the material discharge port provided in the upper part of the hopper.

Here, the airflow generating means provided in the middle of the circulation path may be an air suction means such as a blower, and the air suction means is operated to be provided in the discharge pipe from the middle of the circulation path. From the material suction port toward the material discharge port provided in the upper part of the hopper to generate an air current flowing through the circulation path, and apply a negative pressure to the material suction port side to remove the dried resin material from the hopper. Some may be forcibly sucked into the circulation path.

Further, when air is taken into the circulation path by a heating means such as a heater when air is blown into the circulation path by an air suction means such as a blower, the temperature in the hopper can be increased by heating the air to a predetermined temperature in advance. Since the lowering can be prevented, the drying conditions of the resin material after the drying process accommodated in the hopper can be prevented from being further disturbed.

[0016] The hopper dryer according to claim 2 is
The hot air generated from the hot air supply means of the hopper dryer according to claim 1 is diffused and supplied into the hopper from a lower portion of a diffuser cone provided in the hopper and connected to the hot air supply means via an air supply pipe. After that, it is circulated to the hot air supply means by an exhaust gas recovery pipe connecting between the air discharge port provided at the upper part of the hopper and the hot air supply means, is regenerated into hot air by the hot air supply means, and In addition to being circulated, a pipe is connected between the exhaust gas recovery pipe and the airflow generation means, and when the airflow generation means is operated, the exhaust gas in the exhaust gas recovery pipe is supplied to the circulation path through the pipe. In addition, air is circulated from the material suction port provided in the discharge pipe of the hopper to the material discharge port provided in the upper part of the hopper.

[0017] The hopper dryer according to claim 3 is
A flow sensor for detecting a flow of the resin material discharged from the hopper after the drying process is provided in the discharge pipe of the hopper dryer according to claim 1, and the flow sensor discharges the resin material from the hopper within a preset time. When the flow of the resin material after the completion of the drying process is no longer detected, the airflow generating means is automatically operated for a predetermined time.

The hopper dryer according to claim 4 is
The material suction port of the hopper dryer according to any one of claims 1 to 3, further comprising a one-way valve for flowing the resin material after the drying process in which the airflow is sucked only from the material suction port toward the airflow generating means and from the material suction port. A nozzle means having the same.

[0019]

In the hopper dryer according to the first aspect, the material suction port is provided in the discharge pipe of the hopper, and the material discharge port is provided in the discharge pipe in the middle of the circulation path having the material discharge port in the upper part of the hopper. Airflow generating means for generating an airflow flowing through the circulation path from the material suction port to the material discharge port provided at the upper part of the hopper.

The airflow generating means provided in the middle of the circulation path generates an airflow flowing in the circulation path from the material suction port provided in the discharge pipe to the material discharge port provided in the upper part of the hopper. Therefore, when the airflow generating means is operated, the material suction port side has a negative pressure. Thus, when the airflow generating means is operated, a part of the resin material after the drying process in the hopper is sucked by the airflow from the material suction port, and the material discharge port provided at the upper part of the hopper is provided. It can be recirculated to the hopper more cyclically.

Therefore, when the discharge of the resin material stored in the hopper after the drying process is stopped, the speed is set to be gentle enough not to disturb the drying control conditions of the resin material stored in the hopper. Then, if a part of the resin material is forcibly circulated in the circulation path, the resin materials in the hopper are continuously stirred little by little, and the resin materials adhere to each other to form a block. The occurrence of the blocking phenomenon can be prevented.

The blocking phenomenon that the resin materials adhere to each other and block in the hopper is apt to occur when the discharge of the resin material after the drying treatment contained in the hopper is stopped. Therefore, the airflow generating means may be operated at least when the discharge of the resin material after the drying process stored in the hopper is stopped, but the drying process stored in the hopper is performed. The operation may be always performed both when the later discharge of the resin material is performed and when the discharge is stopped.

In the hopper dryer according to the second aspect, a pipe is connected between the exhaust gas recovery pipe and the airflow generation means, and when the airflow generation means is operated, the exhaust gas in the exhaust gas recovery pipe is circulated through the pipe. It is designed to be supplied inside. Therefore, when the discharge of the resin material after the drying treatment stored in the hopper is stopped, if the airflow generating means is operated, the circulation path is not filled with fresh air but with the hopper. Using the supplied exhaust gas,
Since airflow occurs, the temperature inside the hopper is prevented from dropping,
It is possible to prevent the occurrence of a blocking phenomenon in which the resin materials adhere to each other to form a block without disturbing the drying conditions in the hopper.

In the hopper dryer according to the third aspect, the flow meter does not monitor the continuous flow of the resin material having been dried through the discharge pipe and having completed the drying process.
A signal for activating the airflow generating means is output when the flow of the resin material discharged from the discharge pipe and having undergone the drying process has stagnated for a predetermined period of time. For this reason, in the hopper dryer according to the third aspect, when the discharge of the resin material in the hopper is stopped for a preset time and there is a risk of occurrence of blocking, the circulation path is automatically operated for a predetermined time. Can be done.

In the hopper dryer according to the fourth aspect of the present invention, there is provided a nozzle means having a one-way valve for flowing the resin material after the drying process in which the airflow is sucked only from the material suction port toward the airflow generating means and the suction is performed from the material suction port. Therefore, when the airflow generating means is operated, a smooth airflow that constantly flows from the material suction port provided in the discharge pipe of the hopper to the material discharge port provided in the upper part of the hopper is generated in the circulation path. Therefore, a part of the resin material can be forcibly circulated in a smooth air flow.

This prevents the occurrence of a blocking phenomenon in which the resin materials adhere to each other to form a block, and the resin material after the drying treatment in the hopper is cooled at a gentle speed that does not disturb the drying control conditions. Part of the material can be prevented by forced circulation.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail based on preferred embodiments of the present invention. (Embodiment 1) FIG. 1 is a sectional side view schematically showing a main part of a hopper dryer according to the present invention.

The hopper dryer A includes a hopper 1 for accommodating a resin material such as pellets, a hot air supply means 2 provided on the hopper 1, a diffuser cone 3 provided in the hopper 1, and a diffuser cone. An air supply pipe 4 connecting between the cone 3 and the hot air supply means 2,
An exhaust gas recovery pipe 5 connecting between the hopper 1 and the hot air supply means 2 is provided.

The hopper 1 has a cylindrical straight body 1a,
A conical portion 1 that tapers downwardly as it goes down
b and a central portion of the conical portion 1b,
A straight tube-shaped discharge pipe 1c for discharging the resin material after being dried and housed in the hopper 1, and an upper part (top plate) 1 thereof
It has a material inlet 1f provided in the central part 1e of d, an air outlet 1g provided on the upper part (top plate) 1d and beside the material inlet 1f.

Above the material inlet 1d of the hopper 1,
For example, a resin material storage hopper 6 in which a resin material to be dried is stored is provided via a material cutting shutter 7. Also, the discharge pipe 1c of the hopper 1
Below, a material transport pipe (not shown) and a material input port (not shown) of a molding machine or the like are connected.

The hot air supply means 2 includes a heating means (not shown) for heating and drying air and the like, and a blowing means (not shown) such as a blower for supplying hot air into the hopper 1. I have. One end 3a of the diffuser cone 3 is connected to the air supply pipe 4 connected to the hot air supply means 2 on the side of the straight body 1a of the hopper 1, and the lower part 3b is connected to the discharge pipe 1c of the hopper 1. The opening 3c for diffusing and supplying the hot air supplied from the hot air supply means 2 into the hopper 1 and the outside of the opening 3c are provided in the lower portion 3b. A plurality of small holes 3d formed in the outer peripheral surface 3e are provided.

The exhaust gas recovery pipe 5 is provided so as to connect between an air discharge port 1g provided in an upper portion (top plate) 1d of the hopper 1 and the hot air supply means 2. Then, the hot air generated by the hot air supply means 2 is diffused and supplied into the hopper 1 from the opening 3c of the lower portion 3b of the diffuser cone 3 and the small holes 3d formed on the outer peripheral surface outside the opening 3c. The air is circulated to the hot air supply means 2 through an air discharge port 1g provided in an upper portion (top plate) 1d of the hopper 1 and an exhaust gas recovery pipe 5, and is regenerated into hot air by the hot air supply means 2, and the hopper 1 It is made to circulate inside.

The hopper dryer A is newly provided with the following configuration in addition to the above configuration. That is, in the hopper dryer A, a material suction port 1h is opened in a side wall of the discharge pipe 1c, and a material discharge port 1i is opened in an upper portion (top plate) 1d of the hopper 1.
A circulation path 8 connects the material suction port 1h and the material discharge port 1i.

In the middle of the circulation path 8, an air blowing means such as a blower is provided as the air flow generating means 9.
A pipe 11 is connected between the exhaust gas recovery pipe 5 and the air suction side of the air flow generation means 9, and when the air flow generation means 9 is operated, the exhaust gas in the exhaust gas recovery pipe 5 is discharged. The air is sucked by the generating means 9 and sent to the airflow generating means 9 through the pipe 11, and the air is blown from the airflow generating means 9 in the direction of the material discharge port 1 i provided in the upper portion (top plate) 1 d of the hopper 1. It is supposed to be.

In this example, a branch pipe 8a is connected in the middle of the circulation path 8 so as to be substantially vertical, an air blowing side of the blower is connected to the tip of the branch pipe 8a, and the air suction of the blower is performed. When the blower is driven, the gas in the pipe 11 is sucked into the blower, and then the gas is pressure-fed upward from below the branch pipe 8a from the air blowing side of the blower. By doing so, the resin material such as resin pellets is prevented from entering the blower.

Further, in the hopper dryer A, a nozzle means 12 is provided at the tip of the material suction port 1h so as to protrude into the discharge pipe 1c. This nozzle means 12
Inside, a one-way valve (backflow prevention valve) (not shown) for flowing the airflow and the dried resin material sucked from the suction port 12a only from the suction port 12a of the nozzle means 12 to the airflow generation means 9 (not shown) ) Is provided.

When a predetermined amount of resin material is dried by using the hopper dryer A, first, the material cutting shutter 7 is opened for a predetermined time, and the predetermined amount of resin material stored in the material storage hopper is removed. Housed in hopper 1. Next, the hot air supply means 2 is operated to blow hot air of a predetermined temperature into the resin material contained in the hopper 1,
The resin material contained in the hopper 1 is dried.

The resin material after the drying process is
The material is sequentially supplied from a discharge pipe 1c of the hopper 1 to a material transport pipe (not shown) connected to the discharge pipe 1c or a material input port (not shown) of a molding machine or the like. Then, for example, when the resin molding die is replaced, supply of the dried resin material to a material transfer pipe (not shown) or a material input port (not shown) of a molding machine or the like is temporarily stopped. In the case of a stop, the hopper dryer A operates the airflow generating means 9 in such a case.

At this time, in the circulation path 8, a material suction port 1h provided in the discharge pipe 1c of the hopper 1,
An airflow that flows from the suction port 12a of the nozzle means 12 to the material discharge port 1i provided in the upper portion (top plate) 1d of the hopper 1 is generated. At this time, since the material suction port 1h side in the circulation path 8 has a negative pressure, a part of the resin material after the drying process in the hopper 1 is caused to flow from the material suction port 1h by this air flow. It is sucked and circulates back into the hopper 1 from the material discharge port 1i provided in the upper part (top plate) 1d of the hopper 1.

Therefore, when the discharge of the resin material contained in the hopper 1 after the drying process is stopped, the resin material contained in the hopper 1 is not gently disturbed. If a part of the resin material is forcibly circulated in the circulation path 8 at a speed, the resin materials in the hopper 1 are continuously stirred little by little, and the resin materials adhere to each other. The occurrence of the blocking phenomenon of blocking can be prevented.

In this hopper dryer A, a pipe 11 is connected between the exhaust gas recovery pipe 5 and the airflow generation means 9, and when the airflow generation means 9 operates, the exhaust gas in the exhaust gas recovery pipe 5 is removed. It is supplied through a pipe 11 into the circulation path. For this reason, when the discharge of the resin material after the drying process stored in the hopper is stopped,
When the airflow generating means 9 is operated, the airflow is generated in the circulation path 8 using the exhaust gas supplied into the hopper 1 instead of the fresh air as described above.
The temperature inside the hopper 1 does not drop and the drying conditions inside the hopper 1 are not disturbed.

Further, in the hopper dryer A, the nozzle means 12 having a one-way valve for flowing the air-flow only from the material suction port 1h toward the airflow generating means 9 and the resin material subjected to the drying process sucked from the material suction port 1h is used. When the airflow generating means 9 is operated, the material suction port 1 provided in the discharge pipe 1 c of the hopper 1 is always provided in the circulation path 8.
h, a smooth airflow flowing toward the material discharge port 1i provided in the upper portion (top plate) 1d of the hopper 1 is generated. For this reason, a part of the resin material can be forcedly circulated in the circulation path 8 with a smooth air flow.

When the air flow generating means 9 is operated, the nozzle means 12 always enters the circulation path 8 from the material suction port 1h provided in the discharge pipe 1c of the hopper 1 to the upper part (top) of the hopper 1. Plate) is provided to generate a smooth airflow flowing toward the material discharge port 1i provided in the plate 1d. When the airflow generating means 9 is operated, the airflow is always generated in the circulation path 8. If a smooth airflow can be generated that flows from the material suction port 1h provided in the discharge pipe 1c of the hopper 1 to the material discharge port 1i provided in the upper part (top plate) 1d of the hopper 1, Note that it is not necessarily an essential component member device (the same applies to the following embodiments of the invention).

In this example, the supply of the dried resin material to a material transfer pipe (not shown) or a material input port (not shown) of a molding machine or the like is temporarily stopped. Although the example in which the airflow generating means 9 is operated has been described, the dried resin material is supplied to a material transfer pipe (not shown) or a material input port (not shown) of a molding machine or the like. The airflow generating means 9 may always be operated both during the operation and during the time when the supply of the material is temporarily stopped (the same applies to the following embodiments of the invention). (Embodiment 2) FIG. 2 is a cross-sectional side view of a main part schematically showing another example of a hopper dryer according to the present invention.

The configuration of the hopper dryer B is as follows.
Except for the following points, the configuration is the same as that of the hopper dryer A, so that the corresponding members are denoted by the corresponding reference numerals, and description thereof will be omitted. The hopper dryer B is provided on the upper portion (top plate) 1d of the hopper 1 with the hopper 1
An exhaust port 13 for exhausting the used air used for drying the resin material contained in the hopper 1 to the outside of the hopper 1 is provided. The exhaust port 13 is provided with an exhaust duct 14 as necessary. A dust collector (not shown) is connected to the end of the exhaust duct 14, and the used exhaust gas discharged to the atmosphere via the exhaust duct 13 is used. The air is discharged to the atmosphere after being removed by a dust collector (not shown).

Further, in the middle of the circulation path 8 connecting between the material suction port 1h formed in the side wall of the discharge pipe 1c and the material discharge port 1i formed in the upper part (top plate) 1d of the hopper 1, Airflow generating means 19 such as a blower provided to communicate with the atmosphere is provided. In this example, the circulation path 8
, The branch pipe 8a is connected in a substantially vertical direction,
An air blowing side of a blower whose air suction side is connected to the atmosphere is connected to the distal end of the branch pipe 8a. When the blower is driven, the outside air sucked by the blower is separated from the air blowing side of the blower. The resin material such as resin pellets is prevented from entering the blower by being pressure-fed upward from below the branch pipe 8a.

In FIG. 3, reference numeral 20 denotes a filter for removing dust and dust in the air sucked when the airflow generating means 19 is operated, and 21 denotes a filter for adjusting the sucked air to a predetermined humidity. The heating means, such as a heater provided for the above, are shown. When drying a predetermined amount of resin material using the hopper dryer B, first, the material extraction shutter 7 is opened for a predetermined time, and a predetermined amount of resin material stored in the material storage hopper is transferred to the hopper 1.
Housed within.

Next, the hot air supply means 2 is operated to blow hot air at a predetermined temperature into the resin material contained in the hopper 1 to dry the resin material contained in the hopper 1. The resin material after the drying process is sequentially supplied from the discharge pipe 1c of the hopper 1 to a material transport pipe (not shown) connected to the discharge pipe 1c or a material input port (not shown) of a molding machine or the like. It has become so.

For example, when the resin molding die is replaced, supply of the dried resin material to a material transport pipe (not shown) or a material inlet (not shown) of a molding machine or the like is performed. In the case of a temporary stop, the airflow generating means 19 is operated. Then, in the circulation path 8, the air sucked from the airflow generating means 9 flows toward the material discharge port 1 i provided in the upper portion (top plate) 1 d of the hopper 1. The upper part (top plate) 1 of the hopper 1 is passed through a material suction port 1h provided in the discharge pipe 1c of the hopper 1.
An airflow is generated that flows toward the material discharge port 1i provided at d.

At this time, since the material suction port 1h side in the circulation path 8 has a negative pressure, a part of the resin material after the drying process in the hopper 1 is partially sucked by this air flow. Port 1h, in this example, suction port 12 of nozzle means 12
a, and is circulated back into the hopper 1 through the material discharge port 1i provided in the upper portion (top plate) 1d of the hopper 1.

Therefore, when the discharge of the resin material stored in the hopper 1 after the drying process is stopped, the drying control condition of the resin material stored in the hopper 1 is moderate. If a part of the resin material is forcibly circulated in the circulation path 8 at a speed, the resin materials in the hopper 1 are continuously stirred little by little, and the resin materials adhere to each other. The occurrence of the blocking phenomenon of blocking can be prevented. (Embodiment 3) FIG. 3 is a sectional side view schematically showing a main part of another example of a hopper dryer according to the present invention.

The hopper drier C includes a hopper 1
The circulation path can be automatically operated for a predetermined time when the discharge of the resin material in the inside is stopped for a preset time and there is a risk of occurrence of blocking. The configuration of the hopper drier C is the same as that of the hopper drier A except for the following points, and the corresponding members are denoted by the corresponding reference numerals, and the description thereof is omitted.

In the hopper dryer C, a flow sensor 2 for detecting the flow of the resin material having been dried from the hopper 1 and having been dried is placed in the discharge pipe 1c of the hopper 1.
1 is provided. Here, the flow sensor 21 does not monitor the continuous flow of the dried resin material discharged from the discharge pipe 1c, but sets the flow of the dried resin material discharged from the discharge pipe 1c in advance. A signal for activating the airflow generating means is output when the airflow has stagnated for a predetermined time.

When the flow sensor 21 does not detect the flow of the resin material discharged from the hopper 1 after the drying process within a preset time, the airflow generating means 9 is automatically turned on for a predetermined time. It works. For this reason, when the discharge of the resin material in the hopper 1 is stopped for a preset time, and the hopper dryer C
The circuit can be automatically activated for a predetermined time.

The hopper dryers according to the first to third embodiments of the present invention merely show preferred embodiments for explaining the present invention, and the present invention relates to the first embodiment of the present invention.
It should be noted that the present invention is not limited at all by.

[0056]

As described in detail above, claim 1 is as follows.
In the hopper dryers described in Nos. 1 to 4, a material suction port is provided in a discharge pipe of the hopper, and a circulation path having a material discharge port in an upper portion of the hopper, and a material suction port provided in the discharge pipe in the middle of the circulation path. Airflow generating means for generating an airflow flowing through the circulation path toward a material discharge port provided at an upper portion of the hopper.

By operating the airflow generating means, a part of the resin material after the drying process in the hopper is sucked by the airflow from the material suction port, and is provided above the hopper. It can be recirculated to the hopper from the material discharge port. Therefore, when the discharge of the resin material after the drying process accommodated in the hopper is stopped, the resin material is gently slowed down so as not to disturb the drying control conditions of the resin material accommodated in the hopper. If a part of the resin material is forcedly circulated in the circulation path, the resin materials in the hopper are continuously stirred little by little, and the resin materials adhere to each other to form a blocking phenomenon. Occurrence can be prevented.

[Brief description of the drawings]

FIG. 1 is a cross-sectional side view of a main part schematically showing an example of a hopper dryer according to the present invention.

FIG. 2 is a cross-sectional side view of a main part schematically showing another example of the hopper dryer according to the present invention.

FIG. 3 is a cross-sectional side view of a main part schematically showing another example of the hopper dryer according to the present invention.

FIG. 4 is a cross-sectional side view of a main part schematically showing a conventional hopper dryer.

FIG. 5 is a view schematically showing a phenomenon occurring in a hopper of a conventional hopper dryer.

[Explanation of symbols]

 A, B Hopper dryer according to the present invention 1 Hopper 1a Straight body 1b Conical portion 1c Discharge pipe 1d Upper part of hopper 1f Material inlet 1g Air outlet 1h Material suction port 1i Material outlet 2 Hot air supply means 3 Diffuser cone 4 Air supply pipe 5 Exhaust gas recovery pipe 8 Circulation path 9, 19 Air flow generation means 12 Nozzle means 21 Flow sensor

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-7-332851 (JP, A) JP-A-7-190616 (JP, A) JP-A-7-103655 (JP, A) JP-A-58-1983 74308 (JP, A) Fully open sho 59-75688 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F26B 21/00

Claims (4)

(57) [Claims] 1. A hot air generated by a hot air supply means attached to a hopper is blown into a resin material to be dried contained in a hopper to dry the resin material contained in the hopper. A hopper dryer configured to discharge the dried resin material from a discharge pipe provided at the bottom of the hopper, wherein a material suction port is provided in the discharge pipe, and a material discharge port is provided in an upper portion of the hopper. A circulation path having the airflow flowing in the circulation path from the material suction port provided in the discharge pipe to the material discharge port provided in the upper part of the hopper in the middle of the circulation path. Airflow generating means, at least when the dried resin material is not discharged from the discharge pipe of the hopper, the airflow generating means is operated, An airflow circulating in the circulation path was generated from the material suction port provided in the discharge pipe toward the material discharge port provided in the upper part of the hopper, and was contained in the hopper by the airflow. A part of the resin material after the drying process is sucked from the material suction port provided in the discharge pipe, and is circulated to the inside of the hopper from a material discharge port provided in an upper part of the hopper. Hopper dryer. 2. The hot air generated by the hot air supply means is:
After being diffused and supplied into the hopper from a lower part of a diffuser cone provided in the hopper and connected to the hot air supply means via an air supply pipe, an air outlet provided in an upper part of the hopper and the hot air The hot air supply means is cyclically supplied to the hot air supply means by an exhaust gas recovery pipe connected to the supply means, is regenerated into hot air by the hot air supply means, and is circulated and circulated in the hopper. A pipe is connected between a gas recovery pipe and the airflow generation means, and when the airflow generation means is operated, exhaust gas in the exhaust gas recovery pipe is supplied into the circulation path through the pipe, and the hopper is discharged. 2. The method according to claim 1, wherein the material is used for an airflow flowing from the material suction port provided in a pipe to the material discharge port provided on an upper portion of the hopper. 3. Hopper dryer. 3. A flow sensor for detecting a flow of the resin material discharged from the hopper after the drying process is provided in the discharge pipe, and the flow sensor is discharged from the hopper within a preset time. 3. The airflow generating means automatically operates for a predetermined time when the flow of the resin material after the drying process is no longer detected.
The hopper dryer according to 1. 4. The material suction port is provided with a nozzle means having a one-way valve for flowing an airflow only from the material suction port to the airflow generation means and a resin material after a drying process sucked from the material suction port. Characterized in that:
3. The hopper dryer according to any one of 3.