JPH1130476A - Drying method and drying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress discharge of HC and a solvent content in the middle of conveyance to the drier and to increase a moisture content by a method wherein particles used for drying are conveyed by a superheated steam current for predrying, and the particles are collected by a solid gas separator and fed in the drier. SOLUTION: A wet rubber material is dehydrated by a dehydrating machine 11 and further, after crushing is effected by a crusher 12, the crushed rubber material is fed to an air flow drier 21. Superheated steam heated, for example, at approximate 120-150 deg.C by a steam heater 25 is caused to flow by a steam heater 25. A rubber material and steam fed in an air flow drier 21 are conveyed by a superheated water flow and to a solid gas separator 22. A rubber material is collected at the solid gas separator 22 and a rubber material, and gas are separated away from each other. A rubber material is fed in a ventilation type band drier 27 and during conveyance over a band 27a arranged in a multistage, the rubber material is heated by an internal heater 27b and dried by superheated steam.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method and an apparatus for drying wet particles. In particular, it relates to a method and an apparatus suitable for drying wet rubber particles and resin particles.

[0002]

2. Description of the Related Art In a drying process of synthetic rubber, a ventilated band dryer 270 is used as shown in FIG.
This will be described with reference to FIG. First, the water content of 50 wt% WB
(WB: Wet Base = (water content) / (dry particle weight + water content), and so on)
As a result, the water content is dehydrated to about 10 to 20 wt% WB. The rubber material having a water content of about 10 to 20 wt% WB is conveyed by a belt conveyor 70 and sent into a ventilated band dryer 270. The ventilated band dryer 270 is
After a band (conveyor) 27a made of endless wire mesh or perforated plate provided in multiple stages and a heater 27b are provided therein, a rubber material conveyed on the band 27a is supplied from the air inlet 71 and heated by the heater 27b. This is a device for drying by heating with high-temperature air discharged from the exhaust port 72. here,
Each stage is partitioned into a plurality of rooms by partition walls, and a blower is provided for each room or for every one or two rooms to perform the above-described intake / exhaust. In some cases, the air is sent to the next blower in order. Also, the heater 27b
Is generally provided for each room. The rubber material thus dried in the ventilation type band dryer 270 for 40 to 60 minutes is discharged from the ventilation type band dryer 270, and then supplied to the subsequent molding machine 43 via the elevator 44. You.

[0003]

The rubber material conveyed by the belt conveyor 70 and fed into the upper inlet of the ventilation type band dryer 270 has a relatively low temperature of about 50 to 90 ° C. When drying with superheated steam without superheated steam condenses and condenses on the rubber material surface,
Or reabsorbed. Therefore, there is a problem that the moisture content of the rubber material temporarily increases, and as a result, extra time is required for drying in the ventilation type band dryer 270.
The relatively low temperature of 50 to 90 ° C. also causes a prolonged drying time. Also, belt conveyor
While the rubber material is conveyed over the water, water, HC (hydrocarbon), solvent components, etc. evaporate and are released into the atmosphere. HC has an odor, and odor pollution occurs. There is a problem of causing. Further, there is a situation that it is not preferable that the solvent component is released into the atmosphere.
The present invention has been made in view of the above-mentioned problems of a main dryer such as a ventilated band dryer, and in the course of transporting a wet material such as rubber or resin to the main dryer, HC and a solvent component are in the atmosphere. There is no increase in moisture content due to condensation or re-absorption of moisture near the main dryer inlet, and the material to be dried such as rubber and resin is also relatively hot near the main dryer inlet. An object of the present invention is to provide a drying method and a drying apparatus.

[0004]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems by conveying a wet material such as rubber or resin to a main dryer using a superheated steam flow such as superheated steam. . That is, the present invention takes particles to be dried into a transport pipe configured as a superheated steam flow path, transports them by a superheated steam flow, pre-drys them, and uses a solid-gas separator provided at a predetermined portion of the transport pipe to perform particle drying. Is collected and sent to a dryer connected to the solid-gas separator, and the particles are dried in the dryer. Further, the present invention provides a transport pipe for transporting particles to be dried by a superheated steam flow flowing in the pipe and performing preliminary drying, and supplements particles provided in a predetermined portion of the transport pipe and transported in the transport pipe. A solid-gas separator to collect,
A dryer for taking in and drying the particles collected by the solid-gas separator. The drying in the dryer can be performed by, for example, superheated steam.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic diagram showing the configuration of a drying system having a ventilation type band dryer 27 as a main dryer. Hereinafter, description will be given with reference to FIG. First, the water content 50
A rubber material of about wt% WB is dehydrated by the
Dewatered to about 0-15 wt% WB, and further crushed
After being pulverized in 12, a flash dryer 21 which is a superheated steam flow path
Supplied to The temperature at this time is about 60 to 80 ° C. In the flash dryer 21, 20 to 10 blowers 24 are used.
The flow rate is about 0 m / sec.
Superheated steam heated to about 20 to 150 ° C. (heated to a level that does not become saturated steam) is flowing. The rubber material and steam sent into the flash dryer 21 are transported by the superheated steam flow and reach the solid-gas separator 22. During this time, the rubber material is preheated and pre-dried, and when it reaches the solid-gas separator 22, its temperature is 100 to 120.
℃. In the solid-gas separator 22, the rubber material is collected, and the rubber material and the gas are separated. The rubber material is
While being fed into the ventilation type band dryer 27 and being conveyed on the bands 27a provided in multiple stages, it is dried by the superheated steam heated by the heater 27b provided inside.
The temperature of the superheated steam is about 120 to 150 ° C, and the pressure is 0 to
It is 200 mmAqG. This ventilated band dryer 27
The structure of the band 27a and the heater 27b is the same as that of the conventional ventilated band dryer 270, except that there is no suction port 71 for sucking air and no exhaust port 72 for discharging high-temperature air to the atmosphere. Point, and in connection with this, the pressure of the internal superheated steam is detected by the pressure sensor 31 and the controller 32
By controlling the internal pressure of the dryer 27 by opening and closing the valve 33 in accordance with the result, excess steam (water vapor, HC, solvent vapor, etc.) is led to the condenser 34 for condensation. It differs from the conventional ventilated band dryer 270 in that it is collected in the tank 35. The rubber material dried by the ventilation type band dryer 27 is supplied to the rotary valve 28.
After being discharged through a sealing mechanism such as the above, it reaches a molding machine 43 via an elevator 44. On the other hand, the gas (water vapor, HC, solvent vapor) separated by the solid-gas separator 22 is washed by the steam cleaner 23, and then pressurized by the above-described blower 24,
Heated by the steam heater 25 is provided for recirculation to the flash dryer 21. Since this circulation path is communicated with the ventilated band dryer 27, the pressure is reduced.
Similarly to the internal pressure, the gas is controlled by opening and closing the valve 33, and the gas (water vapor, HC, solvent vapor) separated by the solid-gas separator 22 is condensed through the valve 33 and the condenser 34. It will be collected in the tank 35. As described above, in the system shown in FIG. 1, the dewatered rubber particles are taken into the transport pipe configured as a circulation path of the superheated steam flow, transported by the superheated steam flow, preliminarily dried, and provided at a predetermined portion of the transport pipe. The rubber particles are collected by a solid-gas separator, sent into a dryer connected to the solid-gas separator, and conveyed over a band made of a perforated plate provided in the dryer to dry the rubber particles with superheated steam. Then, a function of recovering HC and solvent vapor evaporated from the rubber particles by a condenser provided in a recovery pipe connected to the dryer and sent out of the dryer is realized.

FIG. 3 is a schematic diagram showing the configuration of a drying system having a continuous fluidized-bed dryer 60 as a main dryer. Hereinafter, description will be given with reference to FIG. First, a wet resin material (S
T-based resin) is dehydrated by a dehydrator 11 to obtain a water content of 10 to 40 wt%.
It is dehydrated to about WB, and is supplied to a flash dryer 21 which is a superheated steam flow path via a supply device having a sealing function. The temperature of the resin at this time is 30 to 40 ° C. Flash dryer 21
Inside, a superheated steam having a pressure of 150 Torr by a blower 24 and heated to about 140 ° C. by a steam heater 25 is flowing. Resin particles and superheated steam are supplied to a pulverizer 12
After being dispersed by the convection heat, the sensible heat of the superheated steam causes the air to flow to the continuous fluidized-bed dryer 60 by the flash dryer 21.
The temperature is raised to a boiling point of 60 ° C. under a pressure of 0 Torr and dried to a water content of 5 to 30 wt% WB. The resin particles and the superheated steam dried in the flash dryer 21 are separated by the solid-gas separator 22. The separated resin particles are supplied to a continuous fluidized bed dryer 60.
In this case, no special sealing mechanism is required. This is because the atmosphere before and after the supply from the solid-gas separator 22 is superheated steam at the same pressure. The superheated steam supplied to the continuous fluidized-bed dryer 60 has a pressure of about 150 Torr and a temperature of about 140 ° C., and the sensible heat of the superheated steam causes the resin particles to have a temperature of 80 ° C. and a water content of 0.3 to 4%.
Dry to wt% WB. The dried resin particles are discharged through a discharger 61 having a sealing mechanism. in this way,
In this example, a continuous fluidized bed dryer is used to convert resin particles using superheated steam.
Since it has been conveyed to 60, the drying time in the dryer 60 can be reduced. The superheated steam used for drying in the flash dryer and the superheated steam used for drying in the continuous fluidized-bed dryer 60 are separated from the resin particles by the solid-gas separators 22 and 22a, respectively. Then, the resin particles are further removed and washed by the steam washer 23 to become saturated steam at approximately 60 ° C. This saturated steam
It is heated again by the steam heater 25 to be superheated steam of 140 ° C., and as described above, the pressure is increased by the blower 24,
Again, it is subjected to drying by the flash dryer 21 or the continuous fluidized-bed dryer 60. Further, the pressure in the pipeline constituting the circulating system is always detected by the pressure sensor 31 and the controller detects the pressure.
Based on the result, the controller 32 controls the opening and closing of the valve 33 and condenses excess steam by the condenser 34 provided in the branch pipe 29 on the side of the valve 33. It is configured to separate and collect wastewater and water-insoluble residual solvent by 35. Non-condensable components such as air mixed into the system are released from the vent of the condensation tank 35. As described above, in the system shown in FIG. 3, the dehydrated resin particles are taken into the transport pipe configured as a circulation path of the superheated steam flow, transported by the superheated steam flow, preliminarily dried, and provided at a predetermined portion of the transport pipe. The resin particles are collected by a solid-gas separator, fed into a dryer connected to the solid-gas separator, dried by superheated steam, sent out of the dryer, and separated from the resin particles by a collection pipe connected to the dryer. The evaporated solvent vapor is returned to the transport pipe downstream of the solid-gas separator, and the resin particles are separated from the resin particles by a condenser provided in a branch pipe downstream of the return position and upstream of the intake position. The function of recovering the evaporated solvent vapor is realized.

FIG. 4 is a schematic diagram showing the configuration of a drying system provided with a batch fluidized-bed dryer 60a as a main dryer.
The configuration of FIG. 4 is substantially the same as that of FIG. Hereinafter, description of the same parts as in FIG. 3 will be omitted, and description will be made in accordance with FIG. 3 is the same as in FIG. 3 until the ST resin material reaches the solid-gas separator 22 through the dehydrator 11, the crusher 12, and the flash dryer 21, and when the ST-based resin material reaches the solid-gas separator 22, Resin particles have a boiling point of 60 ° C. under a pressure of 150 Torr due to the sensible heat of superheated steam.
And dried to 5 to 30 wt% WB. The resin particles separated by the solid-gas separator 22 are supplied to the feed hopper 26, and supplied to the batch fluidized bed dryer 60a through a sealing mechanism for sealing between the feed hopper 26 and the batch fluidized bed dryer 60a. Is done. The resin particles sent to the batch fluidized-bed dryer 60a are dried inside by a drying method using hot air. Before the supply, the resin particles are heated to about 60 ° C. as described above. Since it is heated, the drying time in the batch fluidized bed dryer 60a can be shortened. In addition, solid-gas separator
The superheated steam separated at 22 is circulated by a steam washer 23, a steam heater 25, and a blower 24 for reuse, and excess steam is sent to a condenser 34 to be condensed. , The point of separation and recovery in the condensation tank 35,
This is the same as in FIG. As described above, in the system of FIG. 4, the dehydrated resin particles are taken into the transport pipe configured as a circulation path of the superheated steam flow, transported by the superheated steam flow, pre-dried, and provided at a predetermined portion of the transport pipe. The resin particles are collected by the solid-gas separator and sent into a dryer connected to the solid-gas separator, dried and sent out of the dryer, while the solvent vapor evaporated from the resin particles is branched as extra vapor. The function of recovery is realized by a condenser provided in the tube.

In the above description, a ventilation band type dryer, a continuous fluidized bed dryer, and a batch fluidized bed dryer are described. However, the present invention is also applicable to a batch type box type dryer which is a material stationary type dryer. Machine, parallel flow band (tunnel dryer) as material transfer type dryer, jet volume (nozzle jet) dryer, hard-air dryer, cylindrical and groove type stirrer as material stirring type dryer Dryers, disk dryers, rotary dryers, rotary dryers with steam pipes, rotary rotary dryers, other fluidized bed dryers, conical dryers, vibration transport dryers, and spray dryers that are hot air transfer dryers It is also applicable to a flash dryer, a drum dryer that is a cylindrical dryer, and a multi-cylinder dryer.

[0009]

According to the present invention, HC and solvent components are not released into the atmosphere during the transportation of a wet material such as rubber or resin to the main dryer, and the vicinity of the entrance of the main dryer is prevented. There is no increase in water content due to dew condensation or re-absorption of moisture, and the drying time in the main dryer is reduced because the material to be dried, such as rubber and resin, is relatively hot near the entrance of the main dryer. can do.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a configuration of a drying system when the present invention is applied to a ventilation band type dryer.

FIG. 2 is a schematic diagram showing a configuration of a drying system using a conventional ventilation band type dryer.

FIG. 3 is a schematic diagram showing a configuration of a drying system when the present invention is applied to a continuous fluidized-bed dryer.

FIG. 4 is a schematic diagram showing a configuration of a drying system when the present invention is applied to a batch fluidized bed dryer.

[Explanation of symbols]

 Reference Signs List 21 air flow dryer 27 ventilation band type dryer 60 continuous fluidized bed dryer 60a batch fluidized bed dryer

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshiro Fujii 2--11-24 Tsukiji, Chuo-ku, Tokyo Inside Nippon Gosei Rubber Co., Ltd. (72) Kenji Tachibana 1-1-18-1, Kyobashi, Chuo-ku, Tokyo Techno Polymer Co., Ltd. (72) Inventor Yasuhiro Otaka 1-18-1, Kyobashi, Chuo-ku, Tokyo Techno Polymer Co., Ltd.

Claims (2)

[Claims] 1. A particle to be dried is taken into a transfer pipe configured as a superheated steam flow path, transferred by a superheated steam flow and pre-dried, and the particles are separated by a solid-gas separator provided at a predetermined portion of the transfer pipe. A drying method comprising collecting and sending the collected particles into a dryer connected to the solid-gas separator, and drying the particles in the dryer. 2. A transport pipe for transporting particles to be dried by a superheated steam flow flowing in the pipe and performing preliminary drying, and a collecting pipe provided at a predetermined portion of the transport pipe and transporting the particles in the transport pipe. A drying apparatus comprising: a solid-gas separator that performs drying; and a dryer that captures and dries the particles collected by the solid-gas separator.