JP4724674B2 - Continuous dryer - Google Patents

Description

  The present invention is a continuous type used for removal of liquid components such as solvents after polymerization treatment of synthetic resin, recovery of liquid components such as solvents from processing waste liquid, removal of moisture from chemical raw materials and various inorganic substances, etc. It relates to the dryer.

  When the synthetic resin is subjected to a treatment such as polymerization in an organic solvent, it is necessary to perform a drying treatment to remove a liquid component such as a solvent in a subsequent step. In addition, it is necessary to perform a drying process in order to recover a liquid component such as a solvent from the processing waste liquid. Furthermore, a drying process may be required to remove moisture from chemical raw materials and various inorganic substances.

  As a continuous dryer for continuously performing such a drying process, as shown in FIGS. 4 and 5, a horizontal type in which an input port 1a for an object to be processed is provided on one end side and an outlet port 1b is provided on the other end side. A pair of rotating shafts 2 a provided with stirring blades 2 that rotate in opposite directions in the trough 1 are horizontally mounted, and an object to be processed that is input from the input port 1 a is placed in the hollow rotating shaft 2 a or the trough 1. While being indirectly heated with a heat medium passed through the outer jacket 3, it is transferred to the discharge port 1 b while being stirred by the stirring blade 2, and the liquid component contained in the object to be processed is evaporated during this transfer. There are some (see, for example, Patent Document 1).

  In the one described in Patent Document 1, the upper portion of the trough 1 is opened in order to easily remove the liquid component that evaporates from the processing object being transferred through the trough 1, and the opened upper portion has a ceiling 7a and a side wall 7b. Formed in the steam chamber 7 by being surrounded by the end wall 7c, provided with a plurality of exhaust ports 8 at intervals in the length direction on the ceiling 7a, and connecting each exhaust port 8 to a decompression device such as a vacuum pump, A covering member 9 is provided so as to approach the pair of stirring blades 2 and cover the upper side thereof in a range including the whole or most of the evaporation active region of the liquid component from the end portion on the side of the one inlet 1a.

  That is, since the object to be processed immediately after being introduced from the inlet 1a contains a lot of liquid components that easily evaporate, the liquid components are actively present in a predetermined region of the trough 1 on the inlet 1a side. It becomes the evaporation active area to evaporate. In such an evaporation active region, when the vapor chamber 7 is depressurized by a decompression device, a bumping phenomenon in which these liquid components evaporate all at once and a large amount of vapor is generated easily occurs. The solid matter or the liquid matter that is difficult to evaporate is scattered upward and adheres to the ceiling 7a and the walls 7b, 7c forming the vapor chamber 7. As described above, the solid matter or liquid matter adhering to the ceiling 7a or the walls 7b and 7c may be changed by heat deterioration due to heat in the steam chamber 7 with the passage of time, and may be mixed into the object to be processed as foreign matter. is there. Moreover, what adheres to the ceiling 7a may block the exhaust port 8. In order to prevent the solid matter or the liquid matter from adhering to the ceiling 7a or the walls 7b, 7c due to such a bumping phenomenon, the one described in Patent Document 1 has an upper side of each pair of stirring blades 2 in the evaporation active region A covering member 9 is provided so that the vapor flow accompanying the bumping phenomenon is diverted to the downstream side of the evaporation active region without the covering member 9 and led to the exhaust port 8.

Japanese Patent Laid-Open No. 2001-280844

  As described in Patent Document 1, the continuous dryer having a covering member disposed in the evaporation active region can prevent the solid or liquid material from adhering to the ceiling or wall of the vapor chamber due to bumping phenomenon, but the evaporation activity The vapor flow that is led from the area around the covering member to the exhaust port, or the solid powder or splash liquid that is generated downstream of the evaporation active area and mixed into the vapor flow that is led from the upper side of the covering member to the exhaust port, It descends to the upper surface of the covering member and gradually accumulates. Thus, the deposit deposited on the upper surface of the covering member may block the upper side of the covering member serving as a vapor passage, or may change in quality and ignite due to long-time heating.

  Therefore, an object of the present invention is to prevent the solid powder and the splash liquid mixed in the vapor flow from accumulating on the upper surface of the covering member disposed in the evaporation active region of the continuous dryer.

  In order to solve the above-mentioned problems, the present invention is provided with stirring blades rotating in opposite directions in a horizontal trough provided with a workpiece inlet on one end and a discharge outlet on the other end. A pair of rotating shafts are horizontally mounted, the inside of the trough above the stirring blades is formed in a steam chamber, and a plurality of exhaust ports are provided at intervals in the length direction on the ceiling forming the steam chamber. Then, while heating the object to be processed which is input from the input port, it is transferred to the discharge port while being stirred by the stirring blade, and during this transfer, the liquid component contained in the object to be processed is evaporated, The steam is exhausted from the exhaust port, and covers the upper side of each of the stirring blades close to each other within the range including the whole or most of the evaporation active region of the liquid component from the end portion on the trough inlet side. In a continuous dryer provided with a covering member, the covering The material is provided with an opening extending in the axial direction of the rotating shaft on the side where each of the stirring blades rotates downward with respect to the rotating shaft, and an inclined surface inclined downward toward the opening is provided on the upper surface of the covering member. The provided configuration was adopted.

  That is, the cover member is provided with an opening extending in the axial direction of the rotation shaft on the side where each stirring blade rotates downward with respect to the rotation shaft, and an inclined surface that is inclined downward toward the opening on the upper surface of the cover member. By providing, solid powder and splash liquid mixed in the vapor flow and descending to the upper surface of the covering member are dropped along the inclined surface of the upper surface of the covering member into the opening, and are caught in the stirring blade that rotates downward. It was made to adhere to the to-be-processed object and to be transferred together with the to-be-processed object so that the solid powder and the splash liquid were not deposited on the upper surface of the covering member.

  Each of the stirring blades is rotated downward on the center side between the pair of rotation shafts, and an opening provided on the side of the cover member on which the stirring blades rotate downward is provided at the center between the rotation shafts. By making one common on the side, the openings can be formed in one place.

  In the continuous dryer according to the present invention, an opening extending in the axial direction of the rotary shaft is provided on the cover member disposed in the evaporation active region on the side where each stirring blade rotates downward with respect to the rotary shaft. By providing an inclined surface that is inclined downward toward the opening on the upper surface of the member, solid powder and droplet liquid mixed in the vapor flow and descending on the upper surface of the covering member are caused to follow the inclined surface of the upper surface of the covering member. Since it is dropped into the opening and attached to the object to be wound around the stirring blade that rotates downward, it is transferred together with the object to be processed, so that solid powder and splash liquid do not accumulate on the upper surface of the covering member. Can be.

  Each of the stirring blades is rotationally moved downward on the center side between the pair of rotating shafts, and an opening provided on the side where each of the stirring blades of the covering member is rotated downward is provided on the central side between the rotating shafts. By using a common one, the openings can be formed in one place.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 and 2 show a first embodiment. This continuous dryer is a stirring blade that rotates downward in the center in the opposite direction in a horizontal trough 1 having an inlet 1a for a workpiece on one end and an outlet 1b on the other end. 2 is a heating medium that passes through a pair of rotating shafts 2 a provided with 2 and passes through a hollow rotating shaft 2 a and a jacket 3 outside the trough 1, to be processed. The liquid component contained in the object to be processed is evaporated during the transfer while being indirectly heated and transferred to the discharge port 1b while being stirred by the stirring blade 2.

  Each stirring blade 2 has a progressive feed screw 2b in the range from the end of the trough 1 on the inlet 1a side to the outlet 1b, and the range from the outlet 1b to the end of the outlet 1b is excessive. Is returned to the discharge port 1b as a reverse feed screw 2c. In order to enhance the stirring action of the workpiece, the progressive feed screw 2b is provided with a cutout portion 4 in which a part of the outer peripheral portion of the screw is cut off at a position facing the rotation shaft 2a, and one end side of each cutout portion 4 is provided. A scraper 5 is attached. Further, a hood 6 adjacent to the upper part of each stirring blade 2 is provided above the discharge port 1b in order to facilitate discharge of the workpiece.

  The upper part of the trough 1 is opened, and the opened upper part is surrounded by a ceiling 7a, a side wall 7b, and an end wall 7c to be formed in a steam chamber 7, and a plurality of exhaust ports are provided at intervals in the length direction on the ceiling 7a. 8 is provided, and each exhaust port 8 is connected to a vacuum pump (not shown) in order to depressurize the steam chamber 7. Further, in the range of about 50% of the total length from the end portion of the trough 1 serving as an evaporation active region to be described later, the covering member 9 is disposed so as to be close to the pair of stirring blades 2 and to cover the upper side thereof. ing. The covering member 9 is provided with an opening 10 extending in the axial direction of the rotating shaft 2a at the center of the trough 1 in which the respective stirring blades 2 rotating in the opposite directions to each other rotate downward. An inclined surface 9a that is inclined downward is provided.

  Below, the effect | action of the continuous dryer mentioned above is demonstrated. The object to be processed in the trough 1 is dried by being stirred by the stirring blade 2 while being indirectly heated by the heat medium, but the object to be processed immediately after being charged from the charging port 1a contains a lot of liquid components that easily evaporate. Therefore, the region on the inlet 1a side covered with the covering member 9 is an evaporation active region where the liquid component is actively evaporated.

  In the evaporation active region, the vapor chamber 7 is depressurized by the decompression device, so that a bumping phenomenon may occur in which these liquid components evaporate all at once and a large amount of vapor is generated. However, the evaporation active area provided with the cover member 9 is filled with the object to be processed under the cover member 9 and is mostly covered with the cover member 9, so that even if bumping phenomenon occurs. The momentum is weakened, and there is almost no risk that the solid or liquid contained in the vapor flow will scatter upward through the opening 10 of the covering member 9. Even if they are scattered upward, they do not reach the ceiling 7a of the steam chamber 7 because of their weak momentum, and descend to the upper surface of the covering member 9 and slide down or flow down along the inclined surface 9a. , Falls into the opening 10. The solid matter or liquid matter that has fallen into the opening 10 adheres to the workpiece to be wound around each stirring blade 2 that rotates downward inside the center, and is transferred to the downstream side together with the workpiece.

  Further, most of the steam generated in the evaporating active area is detoured to the downstream side of the covering member 9 and goes to each exhaust port 8 of the ceiling 7a. Vapor generated downstream from the evaporation active region without the covering member 9 also travels toward the exhaust ports 8. These vapors contain fine solid powder and liquid droplets, and what is contained in the vapor directed to the exhaust port 8 above the covering member 9 falls to the upper surface of the covering member 9 by its own weight. The body and the splash liquid also slide down or flow down along the inclined surface 9 a on the upper surface and fall into the opening 10. Therefore, no solid powder or splash liquid is deposited on the upper surface of the covering member 9. In addition, the to-be-processed object which removed the liquid component which is easy to volatilize, and was transferred to the discharge port 1b is extruded from the discharge port 1b as a powdery or paste-like dry processed material.

Using the above-described continuous dryer (Example) and the conventional continuous dryer shown in FIG. 4 (Comparative Example), the treatment object of the resin solution containing 75% by mass of the solvent was dried. The specifications and operating conditions of these continuous dryers are as follows.
・ Outer diameter of stirring blade: 100 mm
・ Rotation speed of stirring blade: 30-60rpm
-Covering range of cover member: about 50% of the total length of trough
-Heating temperature in the trough: 200 ° C
・ Vacuum chamber pressure reduction: 50-100 torr
-Input amount of workpiece: 24 kg / hr
・ Operating time: 5 hours

  After performing the above-mentioned drying treatment, the amount of deposits on the upper surface of the covering member in the continuous dryers of Examples and Comparative Examples was measured. In the comparative example, about 5 mm of deposit was deposited on the upper surface of the covering member, whereas in the example, almost no deposit was observed.

  FIG. 3 shows a second embodiment. This continuous dryer has the same basic configuration as that of the first embodiment, and the pair of stirring blades 2 rotate outwardly in opposite directions to each other. An opening 10 of the covering member 9 is provided on both sides of the trough 1 where each stirring blade 2 rotates downward, and an inclined surface 9a in which the upper surface of the covering member 9 is inclined downward from the center toward the openings 10 on both sides; Is different. Therefore, in this embodiment, the solid material, liquid material, solid powder, and splash liquid falling on the upper surface of the covering member 9 fall into the openings 10 on both sides of the trough 1 and rotate downward. It adheres to the workpiece to be wound around each stirring blade 2 and is transferred to the downstream side together with the workpiece.

In each of the above-described embodiments, the covering member covering range of the evaporation active region is set to about 50% of the total length of the trough. Since it differs, the arrangement | positioning range of a covering member is good to change in the range of about 20 to 50% of the full length of a trough according to the length of an evaporation active region. Further, the covering member does not necessarily need to cover the entire area of the evaporation active region, and may cover 70% or more, preferably 90% or more of the entire region. The cover member is composed of units divided in the axial direction, and may be attached and detached in units according to a desired arrangement range.
As a member,

  In each of the above-described embodiments, the workpiece inlet and outlet are provided on the lower side of the trough. However, these inlet and outlet can be provided on the side of the trough, and the inlet is covered. A member can be passed through and provided on the upper side of the trough.

The longitudinal cross-sectional view which shows the continuous-type dryer of 1st Embodiment Cross-sectional view along line II-II in FIG. Cross-sectional view showing a continuous dryer according to the second embodiment Longitudinal sectional view showing a conventional continuous dryer Cross-sectional view along line VV in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Trough 1a Input port 1b Discharge port 2 Stirring blade 2a Rotating shaft 2b Forward feed screw 2c Reverse feed screw 3 Jacket 4 Cutout part 5 Scraper 6 Hood 7 Steam chamber 7a Ceiling 7b Side wall 7c End wall 8 Exhaust port 9 Cover member 9a Inclined surface 10 Opening

Claims (2)

  A horizontal trough having a workpiece inlet on one end and a discharge outlet on the other end is provided with a pair of rotating shafts provided with stirring blades rotating in opposite directions. The inside of the trough above the stirring blade is formed in a steam chamber, a plurality of exhaust ports are provided at intervals in the length direction on the ceiling forming the steam chamber, and an object to be processed that is input from the input port While heating, stirring with the stirring blade, the liquid is transferred to the discharge port, the liquid component contained in the object to be processed is evaporated during the transfer, and the vapor is exhausted from the exhaust port. In the continuous drier in which a covering member is provided in the range including the whole or most of the evaporation active region of the liquid component from the inlet side end portion thereof and covering the upper side in the vicinity of the stirring blades. Each stirring blade is opposed to its rotating shaft on the cover member. Te on the side where the rotating movement downwards, the opening extending in the axial direction of the rotary shaft is provided, a continuous dryer, characterized by comprising an inclined surface inclined downward toward the opening on the upper surface of the cover member.   Each of the stirring blades is rotated downward on the center side between the pair of rotation shafts, and an opening provided on the side of the cover member on which the stirring blades rotate downward is provided at the center between the rotation shafts. The continuous dryer according to claim 1, wherein one is common on the side.

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