JP2008275253A - Dryer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dryer capable of surely restraining inconvenience such as fusion and sedimentation of a raw material. <P>SOLUTION: This dryer is constituted by arranging an agitating paddle 6 for maintaining a microscopic clearance with an inner wall of a casing 3 in an outer peripheral part of heating bodies 5, by arranging a rotary shaft 4 in the horizontal direction and a plurality of heating bodies 5 installed at an interval in the axial direction on the rotary shaft 4 and having a heating medium passage 5a inside, in the casing 3 having a raw material input port 1 on one end side in the horizontal direction and having a product discharge port 2 on the other end side. The agitating paddle 6 is formed in a shape having a central part projected to the front side in the rotation direction and both right-left side parts continuing in a shape of retreating to the rear side in the rotational direction from its central part, when viewed from the outer peripheral part of the heating bodies 5. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention provides a rotating shaft along the horizontal direction and a space along the axial direction in the casing having a raw material inlet at one end in the horizontal direction and a product outlet at the other end. A drying apparatus provided with a plurality of heating bodies provided with a passage for a heat medium therein, and provided with a stirring paddle for maintaining a minute gap between the outer periphery of the heating body and the inner wall of the casing About.

  For example, a disk-shaped heating body provided with a passage for a heating medium such as steam or heating liquid rotates at a low speed as the rotating shaft rotates, and the raw material charged into the casing from the raw material charging port is supplied to the drying device. While stirring with a paddle that maintains a minute gap between the inner wall of the casing and contacting with the surface of the high-temperature heating body (heat transfer surface), the product is heated and dried, and the dried product is sent out from the product discharge port (for example, see Patent Document 1). ).

Japanese Patent Publication No.56-36354

  In the conventional drying apparatus, the stirring paddle is constituted by a straight vertical wall (see FIG. 5) having a predetermined height from the outer peripheral portion of the heating body. A strong pressing force acts on the raw material, so that a soft raw material such as resin pellets may be fused to the stirring paddle, while the powder raw material may get over the vertical wall and accumulate behind. In addition, when the vertical wall is disposed obliquely with respect to the rotation direction, the pressing force is reduced because the raw material hitting the stirring paddle escapes along the front surface of the vertical wall, and the fusion is suppressed, Some raw materials are fused near the tip of the slanted vertical wall, and powder raw materials may be deposited from the top of the vertical wall to the back of the vertical wall. It was necessary.

  This invention is made | formed in view of the said situation, The objective is to provide the drying apparatus which can suppress inconveniences, such as a fusion | melting and deposition, reliably.

  The first characteristic configuration of the drying apparatus according to the present invention for achieving the above object is that the stirring paddle projects from the outer peripheral portion of the heating body and a central portion protruding forward in the rotational direction, and It is in the point which is formed in the shape which has the right and left both sides connected in the shape which retreats from the central part to the back side of the direction of rotation.

According to the first characteristic configuration, the raw material that hits the stirring paddle as the heating body rotates is pushed right and left by the central portion protruding forward in the rotational direction, and then retreats from the central portion to the rear side in the rotational direction. It is smoothly fed backward along the left and right sides that are connected in shape. That is, a strong pressing force is not applied to the raw material hitting the stirring paddle, and a state in which the raw material is sent backward and is not easily deposited on the stirring paddle is realized.
Therefore, a drying apparatus that can reliably suppress inconveniences such as fusion and deposition is provided.

  The second characteristic configuration is that, in the first characteristic configuration, the stirring paddle is formed in a triangle whose apex angle is directed forward in the rotational direction when viewed from the outer peripheral portion of the heating body. It is in.

That is, the raw material which hits the stirring paddle can be smoothly pushed right and left by the apex angle. Then, by changing the apex angle, it is possible to adjust to an appropriate state in which no fusion or deposition occurs depending on the raw material conditions.
Therefore, a preferred embodiment of a drying apparatus that can be easily adjusted to suppress inconveniences such as fusion and deposition is provided.

  The third characteristic configuration is the above-described first or second characteristic configuration, wherein the stirring paddle is formed on a bottom plate formed in a shape when viewed from the outer peripheral portion of the heating body, and a rotational direction front end portion of the bottom plate. It is in the point comprised by the standing vertical wall.

  That is, the raw material hitting the paddle for stirring is fed backward along the front surface of the vertical wall, and even when a soft solid raw material such as resin pellets jumps above the vertical wall, it can enter and retreat into the space behind the vertical wall. Therefore, it is avoided that a strong pressing force is exerted between the stirring paddle and the inner wall of the casing, and inconvenience of fusion is prevented. Therefore, a preferred embodiment of a drying apparatus that can more reliably suppress the inconvenience of fusion is provided.

  The fourth characteristic configuration is the above first or second characteristic configuration, wherein the stirring paddle is formed in a shape when viewed from the outer peripheral portion of the heating body, and between the bottom plate and the top plate. It is in the point comprised by the vertical wall erected in.

  That is, the raw material that hits the stirring paddle is sent backward along the front surface of the vertical wall, and even if raw materials such as powder enter the inside of the vertical wall from above the vertical wall, the top plate is effectively prevented. The Therefore, a preferred embodiment of a drying apparatus that can more reliably suppress the inconvenience of deposition is provided.

An embodiment of a drying apparatus according to the present invention will be described below with reference to the drawings.
As shown in FIGS. 1 and 2, the drying apparatus of the present invention is provided along a horizontal direction in a casing 3 having a raw material input port 1 on one end side in the horizontal direction and a product discharge port 2 on the other end side. A rotating shaft 4 and a plurality of heating bodies 5 attached to the rotating shaft 4 at intervals along the axial direction and provided with a heat medium passage 5 a are provided inside the casing 3. A stirring paddle 6 is provided to maintain a minute gap between the inner wall and the inner wall. The stirring paddle 6 is made of stainless steel and buffed on the surface, but is not limited thereto.

  The casing 3 is formed in a U-shaped cross section, and the upper opening is covered with an upper cover 10. The raw material inlet 1 is provided at one end of the upper cover 10, and an evaporative gas outlet for discharging gas (for example, water vapor) evaporated from the raw material to the upper cover 10 at a position away from the raw material inlet 1. 11 is provided. In addition, on the inner side of the casing 3, a hook-like member 12 protruding to the vicinity of the rotating shaft 4 with respect to the space between the adjacent heating bodies 5 is attached, whereby the raw material located in the space between the adjacent heating bodies 5 is attached. This prevents the heating body 5 from rotating (co-rotating) with rotation.

  The rotating shaft 4 is formed as a double pipe of an outer pipe 13 and an inner pipe 14, and an annular space between the outer pipe 13 and the inner pipe 14 is steam supplied from one end side (right side in FIG. 1) of the pipe. It is formed in a feed passage for feeding a heat medium fluid such as a heat medium passage 5a of the heating body 5 to the heat medium fluid. Specifically, a plurality of openings 15 are formed in the outer tube 13 corresponding to the position of the heating body 5, and the heat medium fluid flows into the heat medium passage 5 a outside the outer tube 13 through the openings 15. Yes.

  On the other hand, the inner space of the inner tube 14 is formed as a return passage for returning the cooling fluid recovered from the heat medium passage 5a of the heating body 5 to the outside, and the cooling fluid is returned to one end side of the tube and discharged. It is configured as follows. The case where the heat transfer fluid is steam (steam) will be specifically described. After the steam flows into the heat transfer passage 5a of the heating element 5, the condensed water that is cooled and condensed by drying the raw material is stored in the inner pipe 14. A condensed water return pipe 16 that returns to the inner space is provided. The condensed water return pipe 16 scoops up the condensed water gathered on the outer periphery of the heating body 5 by the opening of the arcuate scooping pipe portion 17 located on the heat medium passage 5a side as the rotating shaft 4 rotates, 14 is formed in a tube shape penetrating the outer tube 13 and the inner tube 14 so as to be sent to the center position of the inner space 14. When the heat medium fluid is a liquid such as warm water or heat medium oil, the heat medium liquid fills the heat medium passage 5a. Therefore, in order to return the heat medium liquid to the return channel, as shown in FIG. Instead of the long scooping pipe portion 17, a straight pipe penetrating from the heat medium passage 5 a to the inner space of the inner pipe 14 can be used.

  Next, another embodiment relating to a passage structure for flowing a heat transfer fluid through the heat transfer passage 5a is shown in FIGS. Also in this form, the rotating shaft 4 is formed as a double tube of the outer tube 13 and the inner tube 14, and flows into the annular space between the outer tube 13 and the inner tube 14 from one end side (right side in FIG. 6) of the tube. The heat medium fluid flows through the plurality of openings 15 formed in the outer tube 13 corresponding to the position of the heating body 5 and flows into the heat medium passage 5a. However, the heat medium fluid flowing into the heat medium passage 5a returns to the annular space between the outer tube 13 and the inner tube 14 through the opening 15, and the annular space is directed toward the other end side (the left side in FIG. 6) of the tube. It differs from the structure shown in FIG. 1 in that it is sent and discharged.

  The stirring paddle 6 forms a minute gap between the bottom wall and the lateral wall of the inner wall of the casing 3, and is 90 around the entire circumference of the disk-shaped heating body 5 when viewed along the axial direction of the rotating shaft 4. Four are arranged at intervals of degrees. It should be noted that the spacing between the stirring paddles 6 is substantially constant so that the number of paddles is increased when the diameter of the heating element 5 is increased, and the number of paddles is decreased when the diameter of the heating element 5 is decreased. It is preferable. As shown in FIGS. 3 and 4, the agitation paddle 6 has a central portion 6a that protrudes forward in the rotational direction when viewed from the outer peripheral portion of the heating body 5, and a rear portion in the rotational direction from the central portion 6a. It is formed in a shape having left and right side portions 6b that are continuous in a shape that recedes to the side. Specifically, the stirring paddle 6 is formed in a triangular shape with the apex angle facing the front side in the rotational direction when viewed from the outer peripheral portion of the heating element 5. However, the tip of the apex angle is formed in a rounded shape to suppress fusion.

  The stirring paddle 6 shown in FIG. 3 includes a bottom plate 18 formed in a shape when viewed from the outer peripheral portion of the heating body 5 and a vertical wall 19 erected at the front end portion in the rotational direction of the bottom plate 18. (A) is an example of a triangular paddle with a large apex angle, and (B) is an example of a triangular paddle with a small apex angle. The stirring paddle 6 shown in FIG. 4 includes a bottom plate 20 and a top plate 21 formed in a shape when viewed from the outer periphery of the heating body 5, and a vertical wall 22 erected between the bottom plate 20 and the top plate 21. This is an example of a triangular paddle configured in a box shape. Since the height of the box-shaped stirring paddle 6 shown in FIG. 4 is lower than that of the stirring paddle 6 shown in FIG. 3, the gap between the inner wall of the casing 3 and the stirring paddle 6 shown in FIG. It becomes narrower than the case of the four box-shaped stirring paddles 6.

  Incidentally, in the present embodiment, nine heating bodies 5 (see FIG. 1) are provided, two feed paddles 7 are attached to the heating body 5 on the side close to the raw material inlet 1, and the following three heating bodies 5 are attached. A triangular paddle 6 having a large apex angle shown in FIG. 3 (a) is attached, and a triangular stirring paddle 6 having a small apex angle shown in FIG. 3 (b) is attached to the next three heating elements 5, A parallel paddle 8 shown in FIG. 5 is attached to the last heating body 5.

  It should be noted that the stirring paddle 6 shown in FIG. 3 and the stirring paddle 6 shown in FIG. 4 are preferably used by appropriately changing depending on the type, material, hardness, and the like of the raw material. Specifically, the stirring paddle 6 in FIG. 3 is suitable for stirring resin pellets and raw materials having a large particle diameter, and the stirring paddle 6 in FIG. 4 is suitable for stirring powder raw materials.

  Here, examples of raw materials that can be suitably dried by the present drying apparatus include powder particles (particles such as powder and pellets) that easily adhere, various resins (polyester, polyamide, vinyl acetate, etc.), foods (Corn starch, etc.), food additives, pigments, and other organic materials with strong adhesion or poor fluidity.

Next, an example of the operating conditions of this drying apparatus will be described. Here, an example of a continuous operation in which the dried product is continuously discharged while continuously supplying the raw material is shown, but a batch operation in which a predetermined amount of the raw material is charged in a lump, and after the drying process is taken out in a lump But you can.
[Operating condition 1] (Raw material: Polyamide powder)
Rotational speed (disk outer edge): peripheral speed 0.6m / s
In-machine temperature: 250 ℃
Heat medium temperature (inlet temperature, outlet temperature): Heat medium oil, inlet 260 ℃-> outlet 240 ℃
Processing capacity: 400kg / h (raw material continuous supply, continuous discharge operation)
Processing time (residence time): 5hr
Raw material moisture: 5%
Product moisture: 0.05%
[Operating condition 2] (Raw material: Polyester pellets)
Rotational speed (disk outer edge): peripheral speed 0.4m / s
In-machine temperature: 115 ° C
Heat medium temperature (inlet temperature, outlet temperature): Steam 120 ° C (Inlet and outlet 120 ° C)
Processing capacity: 200kg / h (raw material continuous supply, continuous discharge operation)
Processing time (residence time): 30min
Raw material moisture: 0.4%
Product moisture: 0.1%

  The drying apparatus according to the present invention prevents the occurrence of fusion, deposition, etc. in the apparatus for drying objects having various characteristics such as ease of softening, fluidity, and particle size (granular or powder). However, it can be suitably used when drying.

Front sectional view of a drying apparatus according to the present invention Side surface sectional drawing of the drying apparatus which concerns on this invention in the II position of FIG. The perspective view which shows an example of the paddle for stirring used for the drying apparatus which concerns on this invention The perspective view which shows the other example of the paddle for stirring used for the drying apparatus which concerns on this invention A perspective view showing a conventional paddle for stirring Front sectional view of a drying apparatus according to another embodiment of the present invention Side surface sectional drawing in the II position of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Raw material inlet 2 Product outlet 3 Casing 4 Rotating shaft 5 Heating body 5a Heat medium passage 6 Stirring paddle 6a Center part 6b Left and right both sides 7 Feeding paddle 8 Parallel paddle 10 Upper cover 11 Evaporative gas outlet 12 Spear-shaped member 13 Outside Pipe 14 Inner pipe 15 Opening 16 Condensate return pipe 17 Scooping pipe section 18 Bottom plate 19 Vertical wall 20 Bottom plate 21 Top plate 22 Vertical wall

Claims (4)

In a casing having a raw material input port on one end side in the horizontal direction and a product discharge port on the other end side, the rotary shaft along the horizontal direction is attached to the rotary shaft at intervals along the axial direction, and A plurality of heating elements provided with a heat medium passage inside are provided,
A drying device provided with a stirring paddle for maintaining a minute gap between the outer periphery of the heating body and the inner wall of the casing,
The agitation paddle has a central part protruding to the front side in the rotation direction when viewed from the outer peripheral part of the heating element and left and right side parts connected in a shape retreating from the central part to the rear side in the rotation direction Formed in the drying device.   The drying apparatus according to claim 1, wherein the stirring paddle is formed in a triangular shape with an apex angle directed forward in the rotational direction when viewed from the outer peripheral portion of the heating body.   The said stirring paddle is comprised by the bottom plate formed in the shape when it sees from the outer peripheral part of the said heating body, and the vertical wall erected in the rotation direction front end part of this bottom plate. The drying apparatus described in 1.   The said paddle for stirring is comprised by the bottom plate and top plate formed in the shape when it sees from the outer peripheral part of the said heating body, and the vertical wall erected between this bottom plate and top plate. 2. The drying apparatus according to 2.