JPH0646137B2 - Indirect heating type stirring dryer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Field of Industrial Application The present invention relates to an indirect heating type stirring dryer for drying powdery particles containing moisture by conduction heating.

(2) Conventional Techniques Conventionally, tube type, screw type, member type and other types are well known as indirect heating type stirring and drying machines. Among them, as a member type, for example, JP-A-60-178284
Some are disclosed in Japanese Patent Publication. This is the sixth
As shown in FIG. 7, hollow drying shafts 105 and 106 with stirring members which rotate in mutually opposite directions are horizontally arranged in parallel inside the casing 101, and the drying shafts 105 and 106 have hollow fan-shaped stirring members.
A plurality of 10 are attached at predetermined intervals. That is,
The stirring members 10 are staggered in the axial direction of the shafts 105 and 106, respectively, and are arranged symmetrically with respect to the axial center in the direction intersecting with the axial direction. Also, the stirring member 10
The feed portion 10a is attached to the drying shafts 105 and 106 at a predetermined feed angle α, and the feed portion 10a
A relative angle β of 120 to 170 ° with respect to the feeding portion 10a is formed at the rear end of a, and a central angle δ of 10 to 20% with respect to the central angle γ of the feeding portion.
The return portion 10b having the above is attached.

In the dryer, when the drying shafts 105 and 106 are rotated in opposite directions, the powder or granules supplied from the supply port (not shown) of the casing 101 is fed by the feeding portion 10a of the stirring member 10 attached to the drying shafts 105 and 106. While being gradually transferred rearward, it is heated and dried by the heat medium supplied to the drying shafts 105 and 106 and the hollow inside of the stirring member 10, and is vigorously stirred and crushed by the return portion 10b to be sent backward in the casing 101, It is discharged from a discharge port (not shown).

(3) Problems to be Solved by the Invention However, in the case of the above-mentioned dryer, the stirring member 10 attached to the drying shaft 106 enters between the stirring members 10 attached to the drying shaft 105 to form a staggered shape. Due to the structure arranged as described above, the space shown as a part in FIG. 7 becomes a dead space, and the powdery particles are accumulated there. Therefore, the powder and granules that stay in the dead space and the powder and granules that are sequentially transferred without staying are not uniformly dried, and the quality of the product deteriorates. Further, the stirring member 10 includes a feeding portion 10a and a returning portion 10b.
Since the structure is complicated and the manufacturing is troublesome, the feeding part 10a of the stirring member 10 is mounted at an angle α with respect to the drying shafts 105 and 106, so that the mounting is difficult. There is a problem that it is troublesome and the manufacturing cost is high.

Therefore, the present invention eliminates the problems of the above-mentioned conventional ones, and provides an indirect heating type agitating dryer capable of performing a drying treatment of uniform quality, having a relatively simple structure, easy to manufacture and inexpensive. The purpose is to

(4) Means for Solving the Problems In order to achieve the above object, the present invention provides an indirect heating type stirring dryer as described above, wherein a stirring member is attached to each drying shaft in a direction orthogonal to the axis. And a first stirring member and a second stirring member, wherein the front end surface of the first stirring member in the rotation direction is inclined by a predetermined angle in the feeding direction of the material to be dried with respect to the axis of each drying shaft. And the front end face in the rotation direction of the second stirring member is formed as a return cut face inclined by a predetermined angle to the opposite side of the axis of each drying shaft from the feed direction of the material to be dried. The first and second stirring members are staggered in the axial direction of the respective drying shafts, arranged symmetrically with respect to the axial center in the orthogonal direction, and one drying shaft in the axial direction between the two drying shafts. The other of the first stirring member or the second stirring member is dry. The first stirring member or the second stirring member on the drying shaft is arranged to face the second stirring member or the first stirring member on the one drying shaft.

(5) Action When both drying shafts rotate in opposite directions, the material to be supplied is the first of the stirring members attached to each drying shaft.
By the feed cut surface of the stirring member and the return cut surface of the second stirring member, reciprocating movement is repeated in the axial direction and the radial direction in the vicinity of these members. As a result, the material to be dried is subjected to strong stirring and mixing action, and moves in the casing while being heated and dried by the heating medium supplied to the drying shaft and the hollow insides of the first and second stirring members. When such an object to be dried is moved, the first and second agitating members are mounted on both drying shafts in the above-described arrangement relationship, and the dead space as in the conventional case is eliminated. It will not stay.

(6) Example 1 In FIGS. 1 to 4, reference numeral 1 denotes a double U trough type casing having a hood 2 on an upper portion and a jacket 3 on a side portion,
Inside the casing 1, hollow drying shafts 5 and 6 that rotate in opposite directions are horizontally arranged in parallel. The front ends of the drying shafts 5 and 6 in the rotational direction are formed at 7 on the feed cut surfaces that are inclined at a predetermined angle toward the feeding direction side of the powder or granular material as the material to be dried with respect to the axis of each drying shaft, and A hollow fan-shaped stirring member 10 having a stirring blade 8 and a front end face in the rotation direction are opposite to the feed cut face 7 on the side opposite to the feed direction of the powder and granules with respect to the axis of each drying shaft. A plurality of hollow fan-shaped stirring members 13 formed on the return cut surface 11 inclined at a predetermined angle and having stirring blades 12 on the rear end surface thereof are mounted at predetermined intervals in a direction orthogonal to the axis. Stirring member
10 and 13 are staggered in the axial direction of the drying shafts 5 and 6, respectively, and are arranged so as to be symmetrical with respect to the axial center in the orthogonal direction, and in the axial direction between the drying shafts 5 and 6. Is, for example, the stirring member 10 or 13 on one of the drying shafts 5.
In between, the stirring member 10 or 13 on the other drying shaft 6 is
It is arranged to face the upper stirring member 13 or 10. Feed cut surface 7 and return cut surface 11 of stirring members 10 and 13
Is cut at 45 degrees with respect to the axes of the drying shafts 5 and 6 in this embodiment. However, the cutting angle is not limited to this, and may be in the range of 30 ° to 60 °.
Further, rotary joints 15 and 16 are attached to the ends of the drying shafts 5 and 6 protruding outside the casing 1, and a heat medium (steam, hot water, etc.) is introduced from the rotary joint 15 into the drying shafts 5 and 6. Then, after flowing into the stirring members 10 and 13 through a communication hole (not shown), it returns to the inside of the drying shafts 5 and 6 from the stirring members 10 and 13 through another communication hole (not shown),
It is designed to be discharged from the rotary joint 16. In this embodiment, the rotary joints 15 and 16 are provided at both ends of the drying shafts 5 and 6, but the rotary joints are provided only at one end of the drying shafts 5 and 6 to provide the heat medium stirring member 10 as described above. , 13 may be allowed to flow in or out.

In FIGS. 1 and 2, 17 and 18 are gears that are engaged with each other on the drying shafts 5 and 6, and 20 is a chain sprocket, and a chain (not shown) wound around the sprocket 20 is driven by an electric motor or the like. By doing so, the drying shafts 5 and 6 are rotated via the gears 17 and 18. Also,
Reference numeral 22 is a pipe for supplying the heat medium into the jacket 3, 23 is the same exhaust pipe, 25 is an inlet for feeding the carrier gas into the casing 1, 26 is the same outlet, 27 is a supply port for powder and granular material, and 28 is the same. Indicates the outlet.

Referring to FIG. 5, which is an enlarged cross-sectional view of the main part of FIG. 2, the scraping action and the stirring and mixing action influencing the drying in the embodiment will be described. In the vicinity of 10 and 13, the feed cut surface 7 of the stirring member 10 and the return cut surface 11 of the stirring member 13 exert a strong stirring and mixing action, and the stirring blades 8 and 12 raise the scraping action. Therefore, the agitation and mixing of the powdery particles in the casing 1 in the axial direction and the radial direction are further strongly performed, and the heat transfer coefficient becomes extremely large. The stirring members 10 and 13 are arranged between the stirring members 10 and 13 on the one drying shaft 5 and the stirring members 10 and 13 on the other drying shaft 6 face the stirring members 13 and 10 on the drying shaft 5. Therefore, it is possible to effectively perform stirring and mixing without forming a dead space that causes retention of powder or granules in the casing 1.

The granular material dried as described above moves rearward in the casing 1 due to the positional difference (head difference) of the granular material,
It is discharged from the discharge port 28.

In the above, when drying a powdery material having a large amount of water, the spacing S between the stirring members 10 and 13 is set to a small value (for example, 5 to 10 m /
m) and a small amount (for example, 3 to 15 m / m) in the interval between the stirring members 8 and 12 of the stirring members 10 and 13 and the jacket wall surface, the side surfaces of the stirring members 10 and 13 and the jacket wall surface are It is possible to forcibly scrape off the adhered powder particles.
Therefore, the contact between the heat transfer surfaces of the stirring members 10 and 13 and the wall surface of the jacket and the particles is constantly renewed, and the heat transfer efficiency is significantly increased.

(7) Effect of the Invention Since the present invention is configured as described above, the dead space is eliminated as described above, and the material to be dried is not retained, so that the material to be dried can be dried uniformly.
A product with uniform quality can be obtained. Also,
The stirring member has a simple structure and is easy to manufacture. In addition, the stirring shaft can be mounted in an orthogonal direction without giving a delicate angle to the drying shaft. In addition, since the accumulation is eliminated and the material to be dried is completely discharged, the brand of the material to be dried can be easily replaced, while cleaning of the material to be dried in the casing is almost unnecessary, which is excellent. effective.

[Brief description of drawings]

FIG. 1 is a partially cutaway schematic front view showing an embodiment of the present invention, FIG. 2 is a partially cutaway schematic plan view of the same, and FIG. 3 is a schematic side view taken along the line AA of FIG. Sectional view, FIG. 4 is a partially cutaway perspective view showing the mounting position of the stirring member with respect to the drying shaft, FIG. 5 is an enlarged cross-sectional plan view of an essential part of FIG. 2, and FIG. FIG. 7 and FIG. 7 are schematic plan sectional views of the same. 1 ... Casing, 2 ... Hood 3 ... Jacket, 5, 6 ... Drying shaft 7 ... Feed cutting surface, 8, 12 ... Stirring blade 10, 13 ... Stirring member, 11 ... Return cutting surface

Claims (1)

[Claims] 1. A pair of hollow drying shafts, which rotate in opposite directions to each other, are arranged horizontally in parallel inside a casing, and a hollow fan-shaped stirring member communicates with the hollow inside of the drying shaft on these drying shafts. In an indirect heating type agitator / dryer having a plurality of agitators arranged at intervals, the agitator comprises a first agitator and a second agitator attached to each drying shaft in a direction orthogonal to the axis. The front end face in the rotation direction of the first stirring member is formed as a feed cut face inclined by a predetermined angle with respect to the axis of each drying shaft on the feed direction side of the material to be dried, and in the rotation direction of the second stirring member. The front end surface is formed as a return cut surface inclined by a predetermined angle on the side opposite to the feeding direction of the material to be dried with respect to the axis of each drying shaft, and the first and second stirring members are formed in the axial direction of each drying shaft. Are staggered in each, and in the orthogonal direction The first stirring member or the second stirring member on the other drying shaft is disposed symmetrically with respect to the center and in the axial direction between the two drying shafts, between the first stirring member or the second stirring member on the other drying shaft. But,
An indirect heating type stirring dryer, which is disposed so as to face the second stirring member or the first stirring member on one of the drying shafts.