JP7394658B2 - Stirring shaft and heat exchange device equipped with it - Google Patents

Description

The present invention relates to a stirring shaft having a double pipe structure in which an inner pipe is inserted into a central flow path, and a heat exchange device equipped with the stirring shaft.

Conventionally, a mixer stirring shaft has a double-tube structure, and has an inner tube and an outer tube that constitute the shaft end of the stirring shaft, and a heat medium is fed through the inner tube and the inner tube and the outer tube are connected to each other. A heat medium passage shaft of the type in which the heat medium is returned through an annular gap between the two is known (for example, Patent Document 1).

With this kind of double-tube structure, the heat of the stirring shaft is transmitted to the bearings and gland packing that rotatably support the stirring shaft and are relatively sensitive to high temperatures, which limits the heating temperature of the stirring shaft. There's a problem.

Therefore, a heat insulating sleeve filled with a heat insulating material is placed in contact with the inner surface of the outer tube within the annular gap to prevent the heat of the stirring shaft from being transmitted to the bearing or the gland packing. It is also known to provide a metal case that can be evacuated instead of the heat insulating sleeve, and to evacuate the inside of the case to create a vacuum.

Japanese Unexamined Patent Publication No. 58-207937

However, as in Patent Document 1, it is troublesome to fill the sleeve with heat insulating material, and the overall structure becomes complicated in order to make the sleeve evacuable to a vacuum state. There's a problem.

The present invention has been made in view of the above points, and its purpose is to make it difficult for the heat of the heating medium to be transmitted to heat-sensitive parts such as bearings, while at the same time allowing the stirrer shaft to be heated to as high a temperature as possible. The purpose is to be able to stir things while heating them.

In order to achieve the above object, the first invention targets a stirring shaft in which a heat medium flow path for circulating a heat medium is formed and stirring blades are provided on the outer periphery,
The above stirring shaft is
a cylindrical shaft;
a central flow path passing through the axis of the cylindrical shaft;
a stirring blade extending radially outward from the outer periphery of the cylindrical shaft portion;
an inner tube that is inserted into the central flow path, has one end communicating with the central flow path, and has a heat medium supply/discharge path at its axis, through which a heat medium is supplied or discharged from the other end;
On the outside of the inner tube, between the outer circumference of the inner tube and the inner tube, there is an inner tube outer circumference flow path that communicates with the above-mentioned central flow path, and a vacuum space that covers the outer circumference of the inner tube outer circumference flow path and is sealed inside. A cylindrical vacuum section is provided.

According to the above configuration, a high-temperature heat medium flows through the heat medium supply/discharge path of the inner tube and the outer circumferential flow path of the inner tube, and a vacuum section in which a cylindrical sealed vacuum space surrounding the heat medium is formed. This makes it difficult for heat to be transmitted to the cylindrical shaft portion on the outer periphery. Therefore, even if a high-temperature heat medium is passed through the heat medium supply/discharge path of the inner tube and the outer circumferential flow path of the inner tube, the heat is less likely to be transferred to the bearing portion and gland packing that support the outer circumference of the inner tube. Therefore, even when a heat medium having a temperature as high as possible is allowed to flow inside the stirring shaft, damage to the support portion such as the bearing portion due to heat can be avoided.

In the second invention, in the first invention,
A gap is provided between the outer peripheral surface of the vacuum section and the inner peripheral surface of the cylindrical shaft section to form a continuous air layer in the circumferential direction.

According to the above configuration, since a gap is provided between the outer circumferential surface of the vacuum section and the inner surface of the central flow path to form an air layer, it becomes more difficult for the heat of the vacuum section to be transmitted to the cylindrical shaft section.

In the third invention, in the first or second invention,
The cylindrical shaft portion corresponding to the outer periphery of the vacuum section is covered with a cylindrical sleeve that forms a gap continuous in the circumferential direction between the cylindrical shaft portion and the outer periphery of the cylindrical shaft portion.

According to the above configuration, due to the air layer formed in the gap between the outer periphery of the cylindrical shaft and the inner periphery of the cylindrical sleeve, heat from the cylindrical shaft is further transferred to the bearing and the ground on the outer periphery of the cylindrical sleeve. It becomes difficult to transmit it to the gasket.

The heat exchange device of the fourth invention includes:
A stirring shaft of the third invention,
A rotary device connected to the stirring shaft, which supplies a heat medium to one of the central flow path and the heat medium supply/discharge path, and recovers the heat medium returned from the other of the central flow path and the heat medium supply/discharge path. joint and
a casing that rotatably supports the stirring shaft via a bearing or gland packing;
a heat medium circulation device that supplies and recovers the heat medium via the rotary joint;
The cylindrical sleeve is arranged on the inner periphery of the bearing section or the gland packing.

According to the above configuration, even if a high-temperature heat medium is passed through the rotary joint, the heat is not easily transferred to the bearing parts, etc., so that the workpiece can be effectively heated while preventing damage to the bearing parts etc. due to heat. Can be stirred.

As explained above, according to the present invention, it is possible to stir the object to be processed while heating it with the stirring shaft at a temperature as high as possible while making it difficult for the heat of the heating medium to be transmitted to the heat-sensitive parts such as the bearing portion.

FIG. 3 is an enlarged sectional view of part I in FIG. 2; 1 is a cross-sectional view schematically showing a kneader having a stirring shaft according to an embodiment of the present invention. FIG. 2 is an enlarged sectional view of section III in FIG. 1;

Embodiments of the present invention will be described below based on the drawings.

-Kneading machine configuration-
FIG. 2 shows a kneading machine 10 as a heat exchange device according to the present invention. This kneading machine 10 has, for example, a closed box-shaped casing 1, and a material to be processed (raw material) A This is a continuous kneading machine which is provided with a supply port 2 and a discharge port 3 at the lower end of the other end. Further, a jacket 4 is formed around the outer periphery of the casing 1, and a heat medium C can be circulated within this jacket 4 by a known heat medium circulation device 20.

For example, a pair of stirring shafts 50 are supported on the casing 1 so as to be rotatable by a motor (not shown). For example, one end is pivotally supported by the gland packing 7 and connected to the motor, and the other end is pivotally supported by the gland packing 7 and the bearing part 8 and supplies the heat medium C from the heat medium circulation device 20. and a rotary joint 14 for recovery are connected. For example, one reverse feed screw paddle 16 is fitted onto the rotary joint 14 side of the stirring shaft 50 . A plurality of progressive screw paddles 18 are fitted onto the motor side of the stirring shaft 50 . The shape of this progressive screw paddle 18 is not particularly limited. The reverse screw paddle 16 may be the same as the forward screw paddle 18 attached in the opposite direction.

As shown in FIG. 2, the stirring shaft 50 has a heat medium flow path formed inside thereof through which the heat medium C from the heat medium circulation device 20 flows, and has stirring blades 53 on the outer periphery for stirring the object to be processed A. It is provided. The heat medium flow path includes a center flow path 52, a blade side flow path 54, a heat medium supply/discharge path 55a, etc., which will be described later.

Specifically, the stirring shaft 50 includes a cylindrical shaft portion 51 and a central channel 52 passing through the axis of the cylindrical shaft portion 51 . A plurality of stirring blades 53 are formed protruding from the longitudinal center portion of the cylindrical shaft portion 51, extending radially outward from the outer periphery of the cylindrical shaft portion 51 and provided at intervals in the axial direction. The stirring blade 53 is formed with a blade-side flow path 54 whose one end communicates with the central flow path 52 and which passes through the stirring blade 53 and communicates with the central flow path 52 at the other end. However, the shape of the stirring blade 53 is not particularly limited, and, for example, it may be configured in a continuous spiral shape, or the blade-side channel 54 may not be formed.

A hollow shaft-shaped (tubular) partition member 55 is inserted into the central flow path 52 . As shown in FIG. 1, the partition member 55 is connected to the inner tube 19 of the rotary joint 14 by welding, for example, and is supported so as to rotate integrally with the stirring shaft 50. The partition member 55 has a heat medium supply/discharge path 55a in its axis that communicates with the heat medium supply/discharge path 19a extending to the center of the inner tube 19, and the base end side of the inner tube 19 is connected to the rotary joint 14 to heat the heat medium. The heat medium C is supplied and is configured to be discharged from the other end of the open partition member 55. The partition member 55 is inserted into the central channel 52, partitions the central channel 52 into an upstream side and a downstream side at a position corresponding to the stirring blade 53, communicates the upstream side with one end of the blade side channel 54, and connects the downstream side It has a role of communicating the side with the other end of the blade side flow path 54.

The tip of the central flow path 52 does not extend to the position of the gland packing 7 on the motor side. Therefore, the gland packing 7 on the motor side is hardly affected by the heat of the heat medium C flowing inside the stirring shaft 50.

However, as shown enlarged in FIGS. 1 and 3, on the outside of the inner tube 19 on the rotary joint 14 side, there is an inner tube outer circumferential flow path that communicates with the central flow path 52 between the outer circumference of the inner tube 19 and the outer circumference of the inner tube 19. 21 is formed, the inside of the gland packing 7 on the rotary joint 14 side is easily influenced by the heat medium C.

Therefore, in this embodiment, the outer periphery of the inner tube outer peripheral flow path 21 is covered with a cylindrical vacuum section 22 in which a vacuum space is formed. For example, this cylindrical vacuum part 22 has an inner diameter that is almost the same as the inner diameter of the central flow path 52, so that there is a gap between the outer circumferential surface of the inner tube 19 and between the partition member 55 and the central flow path 52. A space communicating with the formed outer flow path is formed. Its outer diameter is set to a size that can form an appropriate vacuum space inside. This vacuum space is sealed to a pressure of, for example, 10 ⁻² to 10 ⁻⁴ Pa during molding of the inner tube 19. For example, a first pipe 19d having an inner diameter equal to that of the central flow path 52 and a second pipe 19e having a larger outer diameter than the first pipe 19d may be hermetically welded between the flange portions 19b and 19c at both ends.

Furthermore, a gap is ensured between the outer circumferential surface of the vacuum section 22 and the inner circumferential surface of the cylindrical shaft section 51 to form an inner air layer 23 that is continuous in the circumferential direction. This gap is ensured by setting the outer diameter of the second pipe 19e smaller than the inner diameter of the through hole (center flow path 52) formed in the cylindrical shaft portion 51.

Furthermore, the cylindrical shaft portion 51 corresponding to the outer periphery of the vacuum section 22 is covered with a cylindrical sleeve 24 that forms a gap continuous in the circumferential direction between the cylindrical shaft portion 51 and the outer periphery of the cylindrical shaft portion 51 . For example, by making the inner diameter of the cylindrical sleeve 24 at the middle in the longitudinal direction larger than at both end portions in the longitudinal direction, a gap is secured between the cylindrical sleeve 24 and the outer periphery of the cylindrical shaft portion 51 . This gap forms an outer air layer 25 that is continuous in the circumferential direction.

-Kneading machine operation-
Next, the operation of the kneader 10 according to this embodiment will be explained.

When the raw material A is supplied into the casing 1 from the supply port 2, the raw material A is sent toward the discharge port 3 side by the feeding action of the progressive screw paddle 18, and is heated by being kneaded by the rotation of the stirring blade 53. After being thoroughly kneaded while stirring, the product is discharged as a product (kneaded material) B from the discharge port 3. At this time, the amount of raw material A supplied is adjusted to adjust the degree of heating.

During this time, the heat medium C is circulated into the jacket 4 of the casing 1 through an inlet/outlet (not shown) to heat the raw material A. For example, the inside of the casing 1 is heated to about 350°C. Further, as shown in FIG. 2, the heat medium C is also supplied from the rotary joint 14 to the heat medium supply/discharge path 55a through the heat medium supply/discharge path 19a of the inner tube 19, and from deep inside the central flow path 52, It passes through the outer periphery of the member 55, the blade-side flow path 54, and the inner tube outer peripheral flow path 21 of the inner tube 19, returns to the rotary joint 14, and is returned to the heat medium circulation device 20.

In this embodiment, in order to heat the stirring shaft 50 to about 350° C., which is the same as the inside of the casing 1, a high-temperature heat medium flows through the heat medium supply/discharge path 19a of the inner tube 19 and the inner tube outer peripheral flow path 21. However, the cylindrical vacuum part 22 surrounding the vacuum part 22 makes it difficult for heat to be transferred to the cylindrical shaft part 51 on the outer periphery. Furthermore, since a gap is provided around the outer periphery of the vacuum section 22 to form the inner air layer 23, the heat of the vacuum section 22 is further inhibited from being transmitted to the cylindrical shaft section 51.

Further, the outer air layer 25 formed in the gap on the inner circumference of the cylindrical sleeve 24 makes it even more difficult for the heat from the cylindrical shaft portion 51 to be transmitted to the gland packing 7 and the bearing portion 8.

Therefore, even if the high-temperature heat medium C is passed through the heat medium supply/discharge path 19a of the inner tube 19 and the inner tube outer circumference flow path 21 in order to heat the stirring shaft 50 to about 350° C., which is the same as the inside of the casing 1, the outer circumference Heat is less likely to be transmitted to the gland packing 7 and the bearing portion 8 that support the. Therefore, even if a heat medium having a temperature as high as possible is circulated throughout the inside of the stirring shaft 50, the support parts such as the gland packing 7 and the bearing part 8 can be prevented from being damaged by heat.

In this manner, in this embodiment, a zone can be intentionally set around the vacuum section 22 where the temperature is difficult to be transmitted to the outer periphery of the stirring shaft 50. Since the inner tube 19 is made of a tube, its length, outer diameter, material, etc. can be changed arbitrarily. Moreover, since the inner tube 19 only needs to be replaced when it wears out, replacement can be done easily and at low cost. Furthermore, since the heat insulation performance of the stirring shaft 50 alone can be evaluated, troubles after installation can be effectively prevented. Furthermore, since a vacuum layer and an air layer can be ensured in the stirring shaft 50, the heat insulation effect can be easily improved.

As explained above, according to the stirring shaft 50 according to the present embodiment, the temperature of the stirring shaft 50 to be treated is as high as possible while making it difficult to transfer the heat of the heat medium to the heat-sensitive parts such as the gland packing 7 and the bearing part 8. You can stir things while heating them.

(Other embodiments)
The present invention may have the following configuration for the above embodiment.

That is, in the above embodiment, two stirring shafts 50 are arranged in parallel in the kneading machine 10, but only one stirring shaft 50 may be used.

In the above embodiment, the heat medium C supplied from the rotary joint 14 into the partition member 55 is supplied into the central flow path 52 through the heat medium supply/discharge path 19a and the heat medium supply/discharge path 55a. The heat medium C that is supplied into the central flow path 52 on the outer periphery of the inner tube 19 and flows along the outer periphery of the inner tube 19 and the partition member 55 to the motor side through the blade side flow path 54 is transferred to the heat medium of the partition member 55. The heat medium may be discharged to the rotary joint 14 side through the supply/discharge path 55a and the heat medium supply/discharge path 19a of the inner tube 19.

Note that the above embodiments are essentially preferable examples, and are not intended to limit the scope of the present invention, its applications, or uses.

1 Casing
2 Supply port
3 Outlet
4 Jacket
7 Gland packing
8 Bearing section
10 Kneader (heat exchange device)
14 Rotary joint
16 Screw paddle for reverse feed
18 Screw paddle for progressive feeding
19 Inner tube
19a Heat medium supply/discharge path
19b, 19c flange part
19d 1st pipe
19e 2nd pipe
20 Heat medium circulation device
21 Inner tube outer circumference flow path
22 Vacuum section
23 Inner air layer
24 Cylindrical sleeve
25 Outer air layer
50 Stirring shaft
51 Cylindrical shaft part
52 Central channel
53 Stirring blade
54 Vane side flow path
55 Partition member
55a Heat medium supply/discharge path
A Raw material
B Product
C heat medium

Claims (3)

A stirring shaft in which a heat medium flow path for circulating a heat medium is formed, and stirring blades are provided on the outer periphery,
a cylindrical shaft;
a central flow path passing through the axis of the cylindrical shaft;
a stirring blade extending radially outward from the outer periphery of the cylindrical shaft portion;
an inner tube inserted into the central flow path, having a heat medium supply/discharge path (19a, 55a) therein, one end communicating with the central flow path, and a heat medium being supplied or discharged from the other end; Ori,
On the outside of the inner tube, there is an inner tube outer circumference flow path that communicates with the center flow path, and an inner tube outer circumference flow path that covers the outer circumference of the inner tube outer circumference flow path and is rotatably supported by a bearing part. a cylindrical vacuum part in which a sealed vacuum space is formed in the region of the cylindrical shaft part ;
By being blocked by the flange portions (19b, 19c) provided on the outer periphery of the inner tube, air continues in the circumferential direction between the outer circumferential surface of the vacuum portion and the inner circumferential surface of the cylindrical shaft portion. A gap is formed to form the layer (23)
A stirring shaft characterized by: The stirring shaft according to claim 1 ,
The cylindrical shaft portion corresponding to the outer periphery of the vacuum section is covered with a cylindrical sleeve that forms a gap continuous in the circumferential direction between the cylindrical shaft portion and the outer periphery of the cylindrical shaft portion. shaft. The stirring shaft according to claim 2 ,
A rotary device connected to the stirring shaft, which supplies a heat medium to one of the central flow path and the heat medium supply/discharge path, and recovers the heat medium returned from the other of the central flow path and the heat medium supply/discharge path. joint and
a casing that rotatably supports the stirring shaft via the bearing part ;
a heat medium circulation device that supplies and recovers the heat medium via the rotary joint;
A heat exchange device characterized in that the cylindrical sleeve is disposed on an inner periphery of the bearing portion .

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