JPH0760094A - Bearing device of stirrer for tank - Google Patents

Abstract

PURPOSE:To realize a bearing device of a stirrer for a tank withstanding long- term use without generating trouble in extremely simple constitution. CONSTITUTION:The bearing device of a stirrer for a tank is equipped with a cooling mechanism consisting of the cooling fan 11 attached to the stirring shaft in a bearing box 8 and the suction pipe 12 and the exhaust pipe 13 allowing the interior of the bearing box 8 to communicate with the outside. The cooling fan 11 is opposed to the bearing on the side of the tank 2 and the suction pipe 12 is extended into the bearing box 8 and the extended pipe end thereof is arranged on the upstream side of the internal air stream generated by the cooling fan 11. Further, the exhaust pipe 13 is extended into the bearing box 8 and the extended pipe end thereof is arranged on the downstream side of the internal air stream.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing device for a tank agitator, and more particularly to a bearing device for a tank agitator provided with a cooling mechanism for cooling the bearing of the agitation shaft.

[0002]

2. Description of the Related Art In general, an anaerobic sludge treatment device is provided with a large digestion tank partially buried on the surface of the earth, and organic sludge is introduced into the tank and stirred by a stirrer for digestion treatment. It is like this. The drive shaft of the stirrer that stirs the sludge is driven by an electric motor that is mounted on the tank, and the surrounding of the bearing box that is equipped with a bearing that supports the stirring shaft at the top is buried with concrete to prevent vibration. The structure is adopted.

Therefore, the peripheral portion of the bearing box of the stirrer has poor heat dissipation, and the heat generated in the bearing portion due to the rotation of the stirring shaft tends to stay. On the other hand, the sludge accumulated in the digestion tank and processed is 3
The temperature is controlled to a constant high temperature of about 5 ° C. On the other hand, in the digestive tank agitator in the conventional anaerobic treatment apparatus, it is the actual situation that no measure for cooling the bearing is taken into consideration.

[0004]

DISCLOSURE OF INVENTION Problems to be Solved by the Invention As described above, the digestion tank agitator of the conventional anaerobic sludge treatment device is not provided with the cooling mechanism for cooling the bearing portion. For this reason, the temperature of the bearing on the side of the digestion tank in particular has risen to a high temperature close to the upper limit value of 100 ° C.
When the temperature near the bearing portion becomes high, there is a problem that the bearing may be damaged due to deterioration of the lubricating function of the lubricant and increase in stress of the bearing.

The present invention has been made in order to solve the above problems of the conventional bearing device. The bearing device of the tank agitator has a very simple structure and prevents the bearing portion from reaching a high temperature. The purpose is to realize.

[0006]

SUMMARY OF THE INVENTION The present invention provides a tank for storing an agitated liquid therein, a bearing box provided at the top of the tank, and a bearing provided in the bearing box connected to a drive source on the tank. In a bearing device of a tank stirrer, which is supported and has a stirring shaft with stirring blades mounted on an extension shaft inside, a cooling fan mounted on the stirring shaft inside the bearing box and an intake pipe communicating between the inside and outside of the bearing box And a bearing device for a tank agitator provided with a cooling mechanism including an exhaust pipe.

Further, the cooling fan is opposed to the bearing on the tank side, the intake pipe is extended inside the bearing box, and the pipe end is arranged upstream of the internal air flow generated by the cooling fan. Is configured.

Further, the bearing device of the tank agitator in which the intake pipe is extended to the inside of the bearing box and the pipe end is arranged on the downstream side of the internal air flow is constructed.

[0009]

[Effect] Even in a normal state where stirring is stopped, the intake and exhaust pipes of the cooling mechanism that communicates the inside and outside ventilate the inside by a convection effect caused by the temperature difference in the internal space of the bearing box, and a weak cooling operation is performed. It is being appreciated. When the stirring shaft rotates, the cooling fan rotates at the same time and the positive cooling operation of the bearing cooling mechanism starts.

When the cooling fan rotates with the start of the stirring operation, a forced air passage is formed in the bearing box along the air blowing direction of the cooling fan. Then, low temperature outside air is sucked from the intake pipe and projected onto the lower bearing. The projected cold air removes heat from the lower bearing and is then exhausted to the outside through the exhaust pipe. As a result, the lower bearing, which is surrounded by concrete and supports the stirring shaft, is cooled, and the temperature rise of the bearing portion is suppressed.

[0011]

【Example】

Example 1. Embodiments of the present invention will be described below with reference to the drawings. 1 is a configuration explanatory view of a first embodiment of the present invention, FIG. 2 is a sectional view taken along the line AA of FIG. 1, FIG. 3 is a configuration explanatory view of a digestion tank to which the first embodiment of the present invention is applied, and FIG. FIG. 3 is a partially enlarged explanatory view of a case where the present invention is applied to a bearing device of a digestion tank agitator for treating sludge.

In FIGS. 3 and 4, reference numeral 1 is a digester of an anaerobic sludge treatment facility, 2 is a digestion tank, and 3 is a main body of an agitator provided in the digestion tank 2. A concrete material is used for the digestion tank 2, and its cross section is formed into an oval shape by a PC (prestressed concrete) method as shown in the figure. 4 is a reversible rotation type electric motor mounted on the digestion tank 2, 5 is a coupling, and 6 is a stirring shaft. The stirring shaft 6 is connected to the output shaft 51 of the electric motor 4 via the coupling 5.
Are linked to.

Reference numerals 71 and 72 denote upper and lower bearings for supporting the stirring shaft 6, and 8 denotes a bearing box. The upper bearing 71 and the lower bearing 72 are fixed to the upper wall 81 and the lower wall 82 of the bearing box 8. Reference numeral 61 is a straightening plate, and 62 and 63 are two screws, both of which are mounted on the stirring shaft 6 extending inside the digestion tank 2.

Reference numeral 91 is a screw casing having a narrowed portion 92, and 93 is a draft tube connected to the screw casing 91. Reference numeral 94 is four tie rods that suspend the upper portion of the screw casing 91, and 95 is three pedestals that hold the lower portion of the draft tube 93.

The screw casing 91 and the draft tube 93 are attached to the stirring shaft 6 by the tie rod 91 and the mount 95.
X passing through almost the center of the digestion tank 2 in the vertical direction on the same axis as
Suspended on the X axis. Screw casing 91
The upper and lower ends of the draft tube 93 are opened in a gradually expanding manner, and the screw 63 on the stirring shaft 6 is selected at a position corresponding to the narrow portion 92 as shown in the drawing.

Reference numeral 10 is a bearing cooling mechanism. The bearing cooling mechanism 10 is provided in the bearing box 8, and its detailed configuration is shown in FIGS. 1 and 2. 11 is a cooling fan, 12
Is an intake pipe, and 13 is an exhaust pipe. The fan 11 is provided with four impellers 11a inclined at 45 degrees (FIG. 2), and is fixed to the stirring shaft 6 near the lower bearing 72. Further, the intake pipe 12 and the exhaust pipe 13 are connected to a U vent that opens downward, and are provided at substantially symmetrical positions on the upper wall 81 with the XX axis as the axis of symmetry. C is a concrete layer placed in the bearing box 8, and D is sludge accumulated in the digestion tank 2.

The operation of the embodiment of the present invention having such a configuration will be described below.
It will be described next. When the slurry sludge D is fully introduced into the digestion tank 2 from an inlet (not shown) and the electric motor 4 is energized, the stirring shaft 6 is driven. When the two screws 62 and 63 rotate in the forward direction by the driven stirring shaft 6, the upper screw 62 winds up the surrounding sludge D and concentrates it in the vicinity of the opening of the screw casing 91. At the same time, a dynamic pressure is applied to the sludge D concentrated in the opening by the cooperative operation of the screw 63 rotating on the lower side and the narrow portion 92, so that the draft tube 9
It is drawn into 3 and is strongly sent downward in the pipe.

The sludge D flowing downward in the draft tube 93 is discharged from the lower end and hits the bottom wall of the digestion tank 2 to be dispersed in all directions. Further, after being pushed upward along the left and right side walls, the upper layer portion of the digestion tank 2 is reached. And again, the rotating screw 6
2, 63 forms a continuous continuous flow of sludge D that follows the same route as above.

After a certain period of time, the drive current of the electric motor 4 is switched in the reverse direction. And the screw 62,
The 63 rotates in the reverse direction, and the flow of the sludge D in the draft tube 93 is turned upward. As a result, by the pumping action based on the upward and downward flows in the draft tube 93, the sludge D in the digestion tank 2 as shown by the solid line and the chain line in FIG. 2 is effectively agitated by the reversible agitated flow. . The sludge D after the organic substances are decomposed and methane gas is generated by the treatment is taken out from the digestion tank 2 and transferred to the next treatment step.

In this case, when the stirring operation of the main body 3 of the stirrer accompanying the forward and reverse rotation of the stirring shaft 6 is continued, the upper and lower bearings 7
1, 72 generate heat due to frictional heat of the rotating contact portion. On the other hand, as described above, the sludge D stored and processed in the digestion tank 2 is controlled to a slightly higher constant temperature and biologically decomposed. Moreover, since the peripheral portion of the bearing box 8 is surrounded by the concrete layer C, heat is accumulated and accumulated particularly near the lower bearing 72 near the digestion tank 2. Therefore, if it is left as it is, the temperature of the lower bearing 72 becomes high and there is a possibility that seizure will occur.

However, the cooling fan 11 is rotated at the same time as the stirring shaft 6 is rotated, and the positive cooling operation of the bearing cooling mechanism 10 is started. Even in the normal state, due to the convection action due to the temperature difference in the internal space of the bearing box 8,
The intake and exhaust pipes 12 and 13 communicating between the inside and the outside are ventilated to perform a weak cooling operation of the cooling mechanism 10.

A fan 1 for cooling with the start of the stirring operation
When 1 rotates, a blower path forcibly flowing air is formed in the bearing box 8 along the blowing direction of the cooling fan 11. Then, for example, low temperature outside air is sucked from the right intake pipe 12 and projected onto the lower bearing 72. The projected cold air removes heat from the lower bearing 72, and is then exhausted to the outside from the left exhaust pipe 13. As a result, the lower bearing 72 is cooled by the airflow flowing through the air passage, the temperature rise of the bearing portion is suppressed, and the normal rotation state of the stirring shaft 6 is maintained.

Embodiments 2 and 3 Embodiments 2 and 3 of the present invention are shown in FIGS.
In FIG. 5 showing the second embodiment, an auxiliary pipe 12 a for extension is connected to the intake pipe 12. The connected auxiliary pipe 12a is formed in a loose "dogleg" shape, and its extension end is guided to the upstream side of the air passage formed by the fan 11 and opens. Example 2
According to the configuration, the intake capacity is improved, and the outside air of low temperature is
It is sucked directly into the vicinity of the fan 11 through the intake pipe 12 and the auxiliary pipe 12a. Therefore, the heat dissipation function of the bearing 72 is improved, and the heat dissipation effect higher than that of the first embodiment can be achieved.

In the third embodiment of FIG. 6, an intake pipe 12 with an auxiliary pipe 12a similar to that of FIG. 5 is arranged on the left side. Further, a straight auxiliary pipe 13a is connected to the exhaust pipe 13 on the right side, and an air collecting plate 13 facing the bearing 72 is provided at an extension end thereof.
b is provided. According to the structure of the cooling mechanism 10 of the third embodiment, the exhaust capacity is improved, and the air in the vicinity of the bearing 72 is actively exchanged with the outside air, so that the heat dissipation function of the bearing 72 can be further improved.

The experimental results of the present invention are as follows. As an experimental sample, the height and diameter of the bearing box are about 1700 mm and about 1100 mm, respectively, and a cooling fan with a diameter of 600 mm is installed on the stirring shaft 400 mm away from the bearing box, and the results are measured at 600 rpm. Ventilation rate (l / min) Temperature drop of bearing (° C) Example 3 300 20 Example 2 240 15 Example 1 Almost 0 10

The above embodiment of the present invention has been described by exemplifying the case of one fan having four blades and two intake and exhaust pipes 12 and 13 mounted on the upper wall of the bearing box 8. The number of fans, suction and exhaust pipes, mounting positions, shapes and the like may be changed as appropriate. Further, the case of a concrete digestion tank for sludge treatment has been described as an example, but the present invention is also applied to a bearing device for a stirring shaft of a stirring tank of the same type made of a poor conductor having low thermal conductivity. can do.

[0027]

According to the present invention, a bearing device for a stirrer for a tank is provided with a cooling fan attached to a stirring shaft in a bearing box and a cooling mechanism including an intake pipe and an exhaust pipe communicating the inside and outside of the bearing box. did. Further, the cooling fan is opposed to the bearing on the tank side, the intake pipe is extended inside the bearing box, and the extended pipe end is arranged on the upstream side of the internal air flow generated by the cooling fan. Configured. Further, the bearing device of the tank agitator in which the intake pipe is extended to the inside of the bearing box and the pipe end is arranged on the downstream side of the internal air flow is configured.

As a result, even if the bearing on the digestion tank side surrounded by concrete is constructed, the bearing is always cooled by the cooling mechanism, so that the temperature rise in the vicinity of the bearing is suppressed and the temperature does not become high. In addition, even if the sludge is controlled to a high temperature and biologically treated,
Since the cooling mechanism performs the cooling operation in parallel with the stirring, the upper limit value of the set temperature is never reached.

Therefore, according to the present invention, it is possible to provide a bearing device for an agitator for a tank, which has an extremely simple structure and is free from troubles and can withstand long-term use.

[Brief description of drawings]

FIG. 1 is a configuration explanatory diagram of a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a configuration explanatory diagram of an application example of the first embodiment of the present invention.

FIG. 4 is an enlarged explanatory view of a part of FIG.

FIG. 5 is a configuration explanatory diagram of a second embodiment of the present invention.

FIG. 6 is a structural explanatory view of a third embodiment of the present invention.

[Explanation of symbols]

 2 Digestion tank 3 Main body of stirrer 4 Electric motor (drive source) 6 Stirring shaft 8 Bearing box 10 Cooling mechanism 11 Fan 12 Intake pipe 13 Exhaust pipe 62 Screw (stirring blade) 63 Screw (stirring blade) 71 Upper bearing 72 Lower bearing 81 Above Wall 82 Lower wall 91 Screw casing 93 Draft tube C Concrete layer D Sludge (stirring liquid)

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[Procedure amendment]

[Submission date] February 8, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 3

[Correction method] Change

[Correction content]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0003

[Correction method] Change

[Correction content]

Therefore, the peripheral portion of the bearing box of the stirrer has poor heat dissipation, and the heat generated in the bearing portion due to the rotation of the stirring shaft tends to stay. On the other hand, the sludge accumulated in the digestion tank and processed is 3
The temperature is controlled to a constant high temperature of about 5 ° C. On the other hand, in the digestive tank agitator in the conventional anaerobic sludge treatment device, it is the actual situation that no measure for cooling the bearing is taken into consideration.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0004

[Correction method] Change

[Correction content]

[0004]

DISCLOSURE OF INVENTION Problems to be Solved by the Invention As described above, the digestion tank agitator of the conventional anaerobic sludge treatment device is not provided with the cooling mechanism for cooling the bearing portion. For this reason, the temperature of the bearing on the side of the digestion tank in particular has risen to a high temperature close to the upper limit value of 100 ° C.
When the temperature around the bearing portion becomes high, there is a problem that the bearing may be damaged due to deterioration of the lubricating function of the lubricant or increase in stress of the bearing.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction content]

Further, the bearing device of the tank agitator is constructed in which the exhaust pipe is extended inside the bearing box and the pipe end is arranged on the downstream side of the internal air flow.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Name of item to be corrected] 0015

[Correction method] Change

[Correction content]

The screw casing 91 and the draft tube 93 are attached to the stirring shaft 6 by a tie rod 94 and a mount 95.
X passing through almost the center of the digestion tank 2 in the vertical direction on the same axis as
Suspended on the X axis. Screw casing 91
The upper and lower ends of the draft tube 93 are opened in a gradually expanding manner, and the screw 63 on the stirring shaft 6 is selected at a position corresponding to the narrow portion 92 as shown in the drawing.

[Procedure correction 6]

[Document name to be amended] Statement

[Correction target item name] 0021

[Correction method] Change

[Correction content]

However, the cooling fan 11 is rotated at the same time as the stirring shaft 6 is rotated, and the positive cooling operation of the bearing cooling mechanism 10 is started. Even in the normal state where the stirring is stopped, the intake and exhaust pipes 12 and 13 communicating between the inside and the outside are ventilated by the convection action due to the temperature difference in the internal space of the bearing box 8 to perform the weak cooling operation of the cooling mechanism 10. There is.

[Procedure Amendment 7]

[Document name to be amended] Statement

[Name of item to be corrected] 0027

[Correction method] Change

[Correction content]

[0027]

The present invention constitutes a bearing device for a stirrer for a tank provided with a cooling fan attached to a stirring shaft in a bearing box and a cooling mechanism including an intake pipe and an exhaust pipe communicating the inside and outside of the bearing box. did. Further, the cooling fan is opposed to the bearing on the tank side, the intake pipe is extended inside the bearing box, and the extended pipe end is arranged on the upstream side of the internal air flow generated by the cooling fan. Configured. Further, the bearing device of the tank agitator in which the exhaust pipe is extended to the inside of the bearing box and the pipe end is arranged on the downstream side of the internal air flow is configured.

[Procedure Amendment 8]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 1

[Correction method] Change

[Correction content]

[Figure 1]

[Procedure Amendment 9]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 3

[Correction method] Change

[Correction content]

[Figure 3] ─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] February 24, 1994

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 3

[Correction method] Change

[Correction content]

[Figure 3]

Claims (3)

[Claims] 1. A tank for storing an agitated liquid therein, a bearing box provided at the top of the tank, and a driving source on the tank, which is supported by a bearing of the bearing box and extends on an internal extension shaft. A bearing device for a tank stirrer having a stirring shaft equipped with stirring blades, comprising: a cooling fan mounted on the stirring shaft in the bearing box; and an intake pipe and an exhaust pipe communicating the inside and outside of the bearing box. A bearing device for an agitator for a tank, which is provided with a cooling mechanism. 2. The cooling fan is opposed to a bearing on the tank side, the intake pipe is extended to the inside of a bearing box, and a pipe end is arranged on the upstream side of an internal air flow generated by the cooling fan. The bearing device for the agitator for a tank according to claim 1. 3. A bearing device for a stirrer for a tank according to claim 2, wherein the intake pipe is extended inside the bearing box, and a pipe end is arranged on the downstream side of the internal air flow.