JP3961085B2 - Draft tube support device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a draft tube support device provided with a tie rod for fixing a draft tube in a mechanical stirring device used in a digester such as sewage sludge.
[0002]
[Prior art]
In sewage treatment plants, sludge digestion is often performed to reduce sludge, prevent malodors, improve dewatering efficiency, and the like. In the sludge digestion treatment, the sludge in the digestion tank is stirred with a mechanical stirring device or other stirring means to promote sludge digestion.
[0003]
When a mechanical stirrer is used as the stirring means, the stirrer 1 is installed at the center of the upper part of the casing of the digester 2 as shown in FIG. The stirrer 1 includes a vertical stirring pump 4 and a drive motor 3. A draft tube 5 is installed at the center of the digester 2. The draft tube 5 is supported in a vertical state by a support device including a lower pedestal (not shown) and an upper tie rod 7.
[0004]
The stirring pump 4 is provided with a rectifying disk 14, an upper stage impeller 15, and a lower stage impeller 16 on a shaft 13. The lower stage impeller 16 is disposed above the draft tube 5, and has an inner diameter of the draft tube 5 and an outer diameter of the lower stage impeller 16. The cores are inserted so that a uniform gap is formed between them.
[0005]
If the rotation direction of the shaft 13 is changed, the agitation pump 4 can generate either a downward flow or an upward flow by the upper impeller 15 and the lower impeller 16.
Normally, the agitation pump 4 is operated so as to generate a downward flow in the draft tube 5 in which the liquid in the digestion tank 2 is sucked from the upper end of the draft tube 5 and discharged from the lower end. At this time, an upward flow is generated in the digestion tank 5 outside the draft tube 5.
[0006]
As described above, since the liquid is generated in the digestion tank 5 by the operation of the agitation pump 4, the draft tube 5 is shaken, the gap between the draft tube 5 and the lower impeller 16 becomes uneven, and the draft is generated. The tube 5 and the lower impeller 16 may come into contact with each other and cause an accident. Therefore, a turnbuckle 8 for adjusting the tension is provided in the middle of the tie rod 7 that supports the upper portion of the draft tube 5 in order to fix the draft tube 5 so as not to shake.
[0007]
[Problems to be solved by the invention]
However, as shown in FIG. 5, the turnbuckle 8 is one in which a buckle nut 18 provided with a female screw is screwed onto a male screw 17 provided on the tie rod 7, and tension is applied by turning the buckle nut 18. However, it is difficult to accurately grasp the tension applied to the tie rod 7. Therefore, it is difficult to determine whether or not the adjustment of the tension of the tie rod 7 is appropriate when the draft tube 5 is installed.
[0008]
The present invention solves the above-mentioned problem in the support device of the draft tube of the mechanical stirrer of the digester, and easily determines whether or not the adjustment of the tension of the tie rod is appropriate when installing the draft tube. An object of the present invention is to provide a draft tube support device that can be used.
[0009]
[Means for Solving the Problems]
In the draft tube support device of the present invention, the tension for connecting the tie rod via an elastic body that gives a required tension at a predetermined displacement amount in the middle of the tie rod for fixing the draft tube in the mechanical stirring device installed in the digester. The said subject is solved by providing an adjustment tool.
[0010]
When installing the draft tube in the digestion tank, support it vertically with the lower pedestal and upper tie rod, and adjust the tension of the tie rod with the tension adjuster. At this time, if the tension adjuster is adjusted so that the elastic body has a predetermined amount of displacement, the tie rod is given the required tension, so that the draft tube does not shake even if a liquid flow occurs in the digestion tank. To be properly fixed.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is an overall configuration diagram of a digestion tank provided with a draft tube support device according to an embodiment of the present invention, and FIG. 2 is an explanatory diagram of a configuration of a tension adjuster.
[0012]
Here, the stirrer 1 is installed in the center of the upper part of the casing of the digestion tank 2. The stirrer 1 includes a vertical stirring pump 4 and a drive motor 3. A draft tube 5 is installed at the center of the digestion tank 2. The draft tube 5 is supported in a vertical state by a support device including a lower pedestal 6 and an upper tie rod 7.
[0013]
The stirring pump 4 is provided with a rectifying disk 14, an upper stage impeller 15, and a lower stage impeller 16 on a shaft 13. The lower stage impeller 16 is disposed above the draft tube 5, and has an inner diameter of the draft tube 5 and an outer diameter of the lower stage impeller 16. The cores are inserted so that a uniform gap is formed between them.
[0014]
If the rotation direction of the shaft 13 is changed, the agitation pump 4 can generate either a downward flow or an upward flow by the upper impeller 15 and the lower impeller 16.
Normally, the agitation pump 4 is operated so as to generate a downward flow in the draft tube 5 in which the liquid in the digestion tank 2 is sucked from the upper end of the draft tube 5 and discharged from the lower end. At this time, an upward flow is generated in the digestion tank 5 outside the draft tube 5.
[0015]
As described above, since the liquid is generated in the digestion tank 5 by the operation of the agitation pump 4, the draft tube 5 is shaken, the gap between the draft tube 5 and the lower impeller 16 becomes uneven, and the draft is generated. The tube 5 and the lower impeller 16 may come into contact with each other and cause an accident.
[0016]
Therefore, a tension adjuster 9 is provided in the middle of the tie rod 7 that supports the upper portion of the draft tube 5 in order to fix the draft tube 5 so as not to shake.
[0017]
The tension adjuster 9 has a casing 22 fitted with a coil spring 20 and a spring holding plate 21 fixed to the end of one tie rod 7 and a rod insertion hole 25 formed on the spring seat 24 side of the casing 22. Then, the end of the other tie rod 7 provided with the male screw 23 is inserted into the casing 22, a nut 24 is screwed onto the male screw 23, and the tension is adjusted by rotating the nut 24 to compress the coil spring 20. It is supposed to be.
[0018]
The tension of the coil spring 20 with respect to the amount of displacement due to compression is known, and the tension acting on the tie rod 7 can be accurately grasped by measuring the amount of displacement. The amount of displacement due to the compression of the coil spring 20 can be easily recognized as the moving distance of the spring pressing plate 21. Accordingly, when the draft tube 5 is installed, if the coil spring 20 is adjusted so as to have a predetermined displacement amount, a necessary tension is applied to the tie rod 7, so that the draft tube 5 is placed in the digester 2. Even if a flow is generated, it can be appropriately fixed so as not to cause a shake.
[0019]
FIG. 3 is an explanatory diagram of a configuration of another embodiment of the tension adjuster.
In the tension adjuster 9, rod insertion holes 25 and 26 are formed on the spring seat 24 side of the casing 22 on which the coil spring 20 and the spring holding plate 21 are mounted and on the opposite side, respectively. The tip of the tie rod 7 inserted into the casing 22 from the rod insertion hole 25 is fixed to the spring retainer plate 21. The end of the tie rod 7 provided with the male screw 23 is inserted from the rod insertion hole 26 on the opposite side, and a nut 24 is screwed onto the male screw 23. By rotating the nut 24, the coil spring 20 is compressed and tension is applied. It comes to adjust. When the tension adjuster 9 is also installed in the draft tube 5, if the coil spring 20 is adjusted so as to have a predetermined displacement, the tie rod 7 is given a required tension. Even if a liquid flow is generated in 2, it can be appropriately fixed so as not to cause shake.
[0020]
【The invention's effect】
As described above, the support device for the draft tube of the present invention can easily determine whether or not the adjustment of the tension of the tie rod when installing the draft tube is appropriate. Even if this occurs, the draft tube can be appropriately fixed so that no shake occurs.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram of a digestion tank provided with a draft tube support device according to an embodiment of the present invention.
FIG. 2 is an explanatory diagram of a configuration of a tension adjuster.
FIG. 3 is an explanatory diagram of a configuration of another embodiment of a tension adjuster.
FIG. 4 is an enlarged view of the upper part of a conventional digester.
FIG. 5 is an explanatory diagram of a structure of a turnbuckle.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Stirrer 2 Digestion tank 3 Drive motor 4 Stirring pump 5 Draft tube 6 Strut 7 Tie rod 9 Tension adjuster 13 Axis 14 Rectification disk 15 Upper impeller 16 Lower impeller 20 Coil spring 21 Spring presser plate 22 Casing 23 Male screw 24 Nut 25 Insertion Hole 26 Insertion hole

Claims (1)

A draft tube support device comprising a tie rod for fixing a draft tube in a mechanical stirring device installed in a digester,
A draft tube support device comprising a tension adjuster for connecting a tie rod through an elastic body that provides a predetermined tension with a predetermined displacement in the middle of the tie rod.

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