JP3551764B2 - Sludge digester tank agitator carry-in / out device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an apparatus for carrying in and out a stirrer of an anaerobic digestion tank for sludge.
[0002]
[Prior art]
FIG. 7 is a longitudinal sectional view showing the entire configuration of a conventional carry-in / out device of a sludge digestion tank stirrer.
[0003]
In FIG. 7, 1 is a draft tube, 2 is sludge, 2a is the highest level of sludge during normal operation, 2b is the level of sludge during water sealing, and 3 is a leg for fixing the draft tube 1 to the bottom in the digestion tank. , 4 is a concrete slab, 5 is an upper space, 6 is an inspection □, 7 is an inspection □ 6, a water sealing pipe having an upper end connected to 6, 8 is a blind flange, 9 is an underwater stirrer, 11 is a motor of an underwater stirrer 9, 12 is a screw of the underwater stirrer 9, 13 is a ring plate connected to the upper part of the draft tube 1, 14 is a guide rod having one end fixed to the ring plate 13 side and the other end extending vertically upward, in the circumferential direction of the draft tube. It is arranged in several places. The free ends (upper portions) of the guide rods 14 are connected to each other by connection rings 15a and 15b. Reference numeral 16 denotes a slider which is arranged horizontally and slides up and down by sliding on the guide rod 14, and 17 denotes an arm which connects the slider 16 and the underwater stirrer 9, and extends downward from the center of the slider 16. Reference numeral 18 denotes a holder for installing the underwater stirrer 9 directly above the draft tube 1, and 19 denotes a flapper connected to the holder 18, and the wrapper 19 is installed at the top of the draft tube 1. The underwater stirrer 9 is fixed. Reference numeral 21 denotes a hole for mounting a wire (or a chain) provided on the slider 16, reference numeral 22 denotes a hook provided on an upper portion of the inner surface of the water sealing pipe 7, and reference numeral 23 denotes a hoist connecting the mounting hole 21 and the hook 22. The wire (or chain) 24 is a reinforcing rib of the water seal pipe 7. The arrow in the figure indicates the direction in which sludge flows.
[0004]
In such a device, the digestion tank has a draft tube 1 whose upper and lower ends are open, which is erected inside sludge so as to be immersed in sludge. The draft tube 1 is provided with a submersible stirrer 9 inserted right above the draft tube 1 through an inspection port 6. By rotating the screw 12 of the underwater stirrer 9, a downward or upward flow (here, downward) is generated in the draft tube 1, thereby generating a circulating flow by forced convection in the digestion tank, thereby totally removing the sludge 2. It can be agitated. The generated gas is collected in a gas holder (not shown) from a gas vent pipe provided through the outer wall of the digestion tank.
[0005]
In order to check the underwater agitator 9, first raise the water level in the digestion tank to the position of the water surface 2b, and seal the inspection port 6, ie, the lower end opening of the water sealing pipe 7, so that the gas inside is not released to the outside. I do. Next, the blind flange 8 of the inspection port 6 is removed, and the lifting wire (or chain) 23 is hung on a hook of a crane (not shown) and lifted. At this time, the underwater stirrer 9 and the holder 18 also move upward along with the slider 16 via the arm 17, leaving just above the draft tube 1. Thereafter, the slider 16 separates from the guide rod 14, but continues to be lifted upward until the underwater agitator 9 is carried out of the inspection port 6. If the underwater stirrer 9 is carried out of the inspection port 6, the lifting is stopped, and the inspection is performed in that state, or if necessary, the underwater stirrer 9 is moved to the outside of the digestion tank, and then the inspection is performed.
[0006]
Resetting of the underwater stirrer is performed in the reverse procedure. That is, the suspended underwater stirrer 9 is inserted from the inspection port 6 and lowered. At this time, when the slider 16 has descended to the upper end position of the guide rod 14, the slider 16 is temporarily stopped, the slider 16 is aligned with the guide rod 14, and then the descent is continued. The wrapper part 19 is lowered until it hits the upper portion of the draft tube 1. Thereafter, the blind flange 8 of the inspection port 6 is bolted and closed to complete the setting. Here, the length of the arm 17 is such that the position of the slider 16 is above the water level 2b of the sludge at the time of water sealing when the underwater stirrer 9 is installed directly above the draft tube 1 by the holder 18. Has been adjusted.
[0007]
[Problems to be solved by the invention]
However, in the conventional apparatus in which the guide rods 14 are fixed to the ring plate 13 as described above, low-frequency vibrations generated by the underwater stirrer 9 are directly transmitted to the guide rods 14, and if the apparatus is operated for a long time, There were fears of destruction.
[0008]
Such a problem can be solved if a guide rod having a natural frequency outside the resonance frequency band of the low-frequency vibration generated by the underwater stirrer 9 can be used. However, the lower end of the guide rod 14 is fixed to the ring plate 13 above the draft tube, and the upper end of the guide rod 14 is extended to six inspection ports so that the slider 16 is not affected by sludge such as scum. In the conventional device that is extended, the guide rod 14 is inevitably elongated, and the natural frequency of the guide rod 14 is within the resonance frequency band of the low-frequency vibration generated by the underwater stirrer 9. Since the guide rod 14 is easy to enter, and the upper end of the guide rod 14 is basically free, the amplitude becomes large due to resonance when low frequency vibration is transmitted.
[0009]
Further, since the lower part of the guide rod 14 is submerged, there is a problem that the residue is easily entangled.
[0010]
The technical problem of the present invention is to focus on the problems described above, to suppress transmission of vibration from the underwater stirrer side to the guide, and to eliminate sticking of residue to the guide. It is in.
[0011]
[Means for Solving the Problems]
The carry-in / out device of the sludge digestion tank stirrer according to claim 1 of the present invention has the following configuration. That is, in the digestion tank having a draft tube, a device for carrying in and out the underwater stirrer from the inspection port provided immediately above the draft tube in the digestion tank, a water sealing pipe provided in the inspection port and hanging down. A plurality of guides installed at a plurality of positions in the circumferential direction of the inner peripheral surface of the water sealing pipe, each extending in the vertical direction, a slider that slides up and down by these guides, and connects the slider and the underwater agitator below. It comprises an arm and a holder for installing the underwater stirrer directly above the draft tube.
According to the first aspect of the present invention, since each guide is attached to the water sealing pipe and the relationship between each guide and the draft tube is cut off, the low-frequency vibration generated by the underwater stirrer is directly transmitted to each guide. There is no. In other words, the low-frequency vibration generated by this underwater stirrer can only be transmitted through a slider that is detachably connected to each guide with a certain fitting tolerance, and the underwater stirrer is connected directly to the draft tube. After being set on the upper part and centered, the contact between each guide and the slider is almost cut off. For this reason, even if the low-frequency vibration generated by the underwater stirrer is not transmitted to each guide, and even if the vibration is transmitted from the slider to each guide, it is greatly attenuated compared to the conventional one, and the fatigue of each guide is reduced. No destruction is caused.
[0012]
Further, the carrying-in / out device of the sludge digestion tank stirrer according to claim 2 of the present invention is such that the mounting height position of the guide is set such that the lower end thereof is higher than the sludge maximum water surface during normal operation. It is.
According to the second aspect of the present invention, since the guide is mounted at a position higher than the highest water level of the sludge during the normal operation, the residue can be prevented from sticking to the guide, and the relation with the slider can be maintained well.
[0013]
Further, the carrying-in / out device of the sludge digestion tank stirrer according to claim 3 of the present invention is configured such that the guide has a natural frequency deviating from a resonance frequency band of a low-frequency vibration generated by the underwater stirrer. It is.
In the third aspect of the present invention, the guide only needs to secure a sliding stroke required for the slider, and the length and the like can be easily adjusted. For this reason, the length is adjusted so that the natural frequency is out of the resonance frequency band of the low-frequency vibration generated by the underwater stirrer. Also, the shape and mass are adjusted as necessary so as not to hinder the movement of the slider. Thereby, transmission of vibration from the underwater stirrer side to the guide can be significantly suppressed, and reliability can be improved.
[0014]
In addition, the carrying-in / out device of the sludge digestion tank stirrer according to claim 4 of the present invention is configured such that the upper part of the water sealing pipe is formed as a double cylinder, the outer cylinder is fixed to the inspection port side, and The outer diameter is set to be smaller than the inner diameter of the inspection port, a gas vent passage is formed between the inner wall of the inspection port and the outer peripheral surface of the inner cylinder, and the outer cylinder is provided with the digestion gas generated in the digestion tank. A gas vent pipe for extracting gas through the gas vent passage is connected, and a closable gas vent port for replacing digestive gas in the water sealing pipe with outside air at the time of water sealing is provided at the upper part of the inner cylinder. .
According to the fourth aspect of the present invention, since the gas vent passage is formed in the water sealing pipe, the height positional relationship between the gas vent passage and the water sealing pipe becomes clear, and the water level adjustment at the time of water sealing is easy. It becomes.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiment 1 FIG.
Hereinafter, the present invention will be described with reference to the illustrated embodiments.
FIG. 1 is a longitudinal sectional view showing the entire configuration of a carry-in / out device of a sludge digestion tank stirrer according to a first embodiment of the present invention, and FIG. 2 is a longitudinal sectional view showing a water sealing pipe and a guide, which are main parts thereof. 3 is a plan view of FIG. 2, FIG. 4 is a longitudinal sectional view showing the guide mounting portion in an enlarged manner, and FIG. 5 is a graph showing the vibration damping effect of the device of the present invention as compared with the conventional device. The same parts as those of the conventional example are denoted by the same reference numerals, and description thereof will be omitted.
[0016]
The carry-in / out device of the sludge digestion tank stirrer according to the first embodiment is provided with a guide at the time of carrying-in / out of the underwater stirrer 9 at a plurality of circumferential positions on the inner peripheral surface of the water seal pipe 7 connected to the upper end of the inspection □ 6. Are provided with guides 31 extending vertically.
[0017]
More specifically, each of the guides 31 is formed of a pipe, and is attached to the inner peripheral surface of the water sealing pipe 7 via the position adjusting means 32. The position is fixed to be adjustable.
[0018]
The position adjusting means 32 is provided at a plurality of positions in the longitudinal direction of each guide 31, and one end is fixed to the guide 31 by welding or the like, and the other end is orthogonal to the axis of the guide 31, as shown in FIG. And a female member having one end fixed to the inner peripheral surface of the water sealing pipe 7 by welding or the like, the other end protruding in the radial direction, and the male member 32a slidably inserted from the protruding end. It is composed of a member 32b and a set screw (not shown) for fixing the position of the male member 32a. The position (projection height of the male member) with respect to the slider 16 is adjusted at the time of installation, and is fixed after the adjustment. .
[0019]
The length of each guide 31 is set to a length that can secure a sliding stroke required by the slider 16 and is a natural frequency that is out of a resonance frequency band of low-frequency vibration generated by the underwater agitator 9. However, the adjustment of the natural frequency does not necessarily have to be performed only by the length of the guide 31, but can also be adjusted by the shape and the mass. Therefore, each guide 31 does not necessarily need to be constituted by a pipe, and may be constituted by a plate or a solid shaft which does not hinder the movement of the slider 16.
[0020]
Further, the mounting height position of each guide 31 is set such that the lower end thereof is higher than the sludge maximum water level 2a during normal operation. The arrow in the figure indicates the direction in which sludge flows. The rest of the configuration and the operation procedure for loading and unloading the underwater stirrer 9 are the same as those of the above-described conventional example.
[0021]
As described above, in the carry-in / out device of the sludge digestion tank stirrer of the first embodiment, each guide 31 is attached to the water sealing pipe 7 and the relationship between each guide 31 and the draft tube 1 is refused. The low-frequency vibration generated by the stirrer 9 is not directly transmitted to each guide 31. That is, there is only a possibility that the low frequency vibration generated by the underwater stirrer 9 is transmitted through the slider 16 which is detachably connected to the guide 31 with a certain fitting tolerance. After being installed just above and centered, the contact between each guide 31 and the slider 16 is also substantially cut off. For this reason, even if the low-frequency vibration generated by the underwater stirrer 9 is not transmitted to each guide 31, and even if the vibration is transmitted to each guide 31 from the slider 16, as shown in FIG. The guide 31 is attenuated (1/5 or less), so that the guides 31 do not suffer from fatigue failure.
[0022]
In addition, since each guide 31 is mounted at a position higher than the maximum sludge surface 2a during normal operation, the residue does not stick to each guide 31 and the relationship with the slider 16 can be maintained well.
[0023]
In addition, each guide 31 only needs to secure a sliding stroke required for the slider 16, and adjustment of the length and the like is easy. For this reason, it becomes easy to adjust the length so that the natural frequency is out of the resonance frequency band of the low-frequency vibration generated by the underwater stirrer 9.
[0024]
In addition, since each guide 31 is adjusted to have a natural frequency outside the resonance frequency band of the low-frequency vibration generated by the underwater stirrer 9, the vibration from the underwater stirrer 9 is transmitted to each guide 31. Can be greatly suppressed, and the reliability is improved.
[0025]
Embodiment 2. FIG.
FIG. 6 is a longitudinal sectional view showing the entire configuration of the carry-in / out device of the sludge digestion tank stirrer according to the second embodiment of the present invention. In the drawing, the same reference numerals are used for the same parts as those in the second embodiment. And a description thereof will be omitted.
[0026]
The carrying-in / out device of the sludge digestion tank stirrer according to the second embodiment is configured such that the upper part of the water sealing pipe 41 is formed as a double cylinder, and the outer cylinder 41a is fixed to the upper surface of the inspection port of the concrete slab 4. The inner cylinder 41b is set so that its outer diameter is smaller than the inner diameter of the inspection port 6, and a gas vent passage 42 is formed between the inner wall 6a of the inspection port 6 and the inner cylinder outer peripheral surface 41c. ing.
[0027]
Further, the outer cylinder 41a is connected to a gas vent pipe 43 for extracting the digestion gas generated in the digestion tank through the gas vent passage 42 and transporting the digest gas to a gas holder (not shown).
[0028]
Further, at the upper part of the inner cylinder 41b, a plurality of closable gas vent ports 44 for replacing the digestion gas in the water sealing pipe 41 with the outside air at the time of water sealing are provided at a plurality of circumferential positions.
[0029]
Further, a second gas vent pipe 45 is connected to a position different from the gas vent pipe connection part in the outer cylinder 41a, and a safety valve 46 is provided in the middle of the second gas vent pipe 45. The safety valve 46 is set to open when the digestion gas accumulated in the upper space 5 in the digestion tank reaches a predetermined pressure or higher, thereby ensuring safety. The rest of the configuration and the operation procedure for loading / unloading the underwater stirrer 9 are the same as those of the above-described conventional example and the first embodiment.
[0030]
In the carrying-in / out device of the sludge digestion tank stirrer according to the second embodiment, a gas vent pipe 43 or a gas vent pipe with a safety valve (second gas vent pipe) 45 for ensuring safety is provided at the uppermost position of the digestion tank. Is installed, the height positional relationship between the gas vent passage 42 and the water sealing pipe 41 becomes clear, and the water level adjustment at the time of water sealing becomes easy. For this reason, the gas release passage 42 is not erroneously closed due to the rise in the sludge water level at the time of water sealing, and the generated digestive gas is released stably.
[0031]
【The invention's effect】
As described above, according to the first aspect of the present invention, since each guide is attached to the water sealing pipe and the relationship between each guide and the draft tube is cut off, low-frequency vibration generated by the underwater stirrer is applied to each guide. Direct transmission can be prevented. For this reason, it is possible to prevent each guide from causing fatigue failure.
[0032]
According to the second aspect of the present invention, since the guide is mounted at a position higher than the maximum water level of the sludge during the normal operation, the guide does not stick with the residue, and the relationship with the slider can be maintained well. it can.
[0033]
According to the third aspect of the present invention, since the guide has a natural frequency deviating from the resonance frequency band of the low-frequency vibration generated by the underwater stirrer, the vibration from the underwater stirrer is transmitted to the guide. Can be greatly suppressed, and the reliability can be improved.
[0034]
According to the fourth aspect of the present invention, since the gas venting passage is formed in the water sealing pipe, the height positional relationship between the gas venting passage and the water sealing pipe becomes clear, and the water level adjustment at the time of water sealing is easy. It becomes.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing the entire configuration of a carry-in / out device of a sludge digestion tank stirrer according to a first embodiment of the present invention.
FIG. 2 is a longitudinal sectional view showing a water sealing pipe and a guide, which are main parts of a carry-in / out device of the sludge digestion tank stirrer according to the first embodiment.
FIG. 3 is a plan view of FIG. 2;
FIG. 4 is an enlarged longitudinal sectional view showing a guide attachment portion of the carry-in / out device of the sludge digestion tank stirrer according to the first embodiment.
FIG. 5 is a graph showing a vibration damping effect of the device of the present invention as compared with a conventional device.
FIG. 6 is a longitudinal sectional view showing the entire configuration of a carry-in / out device of a sludge digestion tank stirrer according to a second embodiment of the present invention.
FIG. 7 is a longitudinal sectional view showing the entire configuration of a conventional carry-in / out device for a sludge digestion tank stirrer.
[Explanation of symbols]
Reference Signs List 1 Draft tube 6 Inspection port 6a Inspection port inner wall 7 Water seal pipe 9 Underwater agitator 16 Slider 17 Arm 18 Holder 31 Guide 41 Water seal pipe (double cylinder)
41a outer cylinder 41b inner cylinder 41c inner cylinder outer peripheral surface 42 gas vent passage 43 gas vent pipe 44 gas vent port

Claims (4)

A device for carrying a submersible agitator in and out of a digestion tank having a draft tube through an inspection port provided immediately above the draft tube in the digestion tank,
A water sealing pipe provided in the inspection opening and hanging,
Guides are installed at a plurality of locations in the circumferential direction of the inner peripheral surface of the water sealing pipe, each extending vertically.
A slider that slides up and down by sliding on these guides,
An arm connecting the slider and a lower underwater stirrer,
A holder for installing the underwater stirrer directly above the draft tube,
A sludge digestion tank stirrer carry-in / out device characterized by comprising: The sludge digestion tank stirrer carry-in / out device according to claim 1, wherein the guide has an installation height position such that a lower end thereof is higher than a sludge maximum water surface during normal operation. 3. The apparatus according to claim 1, wherein the guide has a natural frequency deviating from a resonance frequency band of a low-frequency vibration generated by the underwater stirrer. The upper part of the water sealing pipe is formed as a double cylinder, the outer cylinder is fixed to the inspection port side, and the outer diameter of the inner cylinder is set smaller than the inner diameter of the inspection port, and the inner wall of the inspection port is A gas vent passage is formed between the outer cylinder and the outer peripheral surface of the inner cylinder, and a gas vent pipe for extracting the digestion gas generated in the digestion tank through the gas vent path is connected to the outer cylinder. The sludge digester according to any one of claims 1 to 3, wherein a closable gas vent port is provided at an upper portion for replacing a digestion gas in the water sealing pipe with outside air at the time of water sealing. Loading / unloading device for tank agitator.

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