JP6516556B2 - Sludge scraping machine and endless chain - Google Patents

Description

  The present invention relates to a sludge scraper for scraping sludge deposited on the bottom of a sedimentation tank and an endless chain used therefor.

  In sewage treatment plants, wastewater treatment plants, water purification plants, etc., sedimentation basins are installed for settling and separating particles contained in treated water. Sludge separated by sedimentation in the sedimentation tank is scraped by a sludge scraper installed inside the sedimentation tank and collected in a sludge pit. Then, the sludge collected in the sludge pit is discharged from the discharge pipe to the outside of the settling tank.

  For example, as described in Patent Document 1, the sludge scraping machine used in the rectangular sedimentation basin includes an endless chain moving on the bottom of the sedimentation basin and the water surface, and a plurality of flights fixed to the endless chain. A chain flight type sludge scraper is known. The chain flight type sludge scraper moves the bottom of the basin and the water surface by the flight fixed to the endless chain, so the sludge accumulated on the bottom of the rectangular sedimentation tank scoops up the scum that floats on the sludge pit and floats on the water surface. It is a device having a function of scraping up to the discharge device.

  A chain-type sludge scraper uses a resin endless chain because of the reduction of power by weight reduction and the reduction of parts replacement frequency. As a specific resin material, polyacetal having high tensile strength and excellent slidability is used for the chain body, and polyamide having excellent slidability is used for the connection pin for connecting the chain body It is done.

JP 2014-240044

In recent years, first settling basins such as sewage treatment plants may be used as rainwater control basins. When used as a rainwater conditioning pond, the water in the sedimentation basin is usually drained so that rainwater can be temporarily stored when there is heavy rainfall or the like.
If the water inside the sedimentation tank is drained in order to use as a rainwater conditioning pond, the residual sludge accumulated in the bottom of the sedimentation tank will rot and generate hydrogen sulfide. A portion of the generated hydrogen sulfide is oxidized in water to become sulfuric acid, and therefore the water remaining in the rainwater conditioning reservoir contains a small amount of sulfuric acid.

Here, it was discovered that when the water was first drained from the sedimentation tank, the water droplets attached to the endless chain were naturally dried to generate a high concentration of sulfuric acid on the endless chain. It has also been found that conventional polyacetal resin chains degrade when exposed to high concentrations of sulfuric acid. Therefore, when using the first settling basin as a rainwater conditioning basin, it is necessary to cope with the replacement frequency by increasing the frequency of the replacement so that problems such as breakage of the resin chain do not occur.
So, in this invention, the tolerance with respect to the high concentration sulfuric acid of an endless chain is heightened, it aims at providing the sludge scraper which has few replacement | exchange frequencies of parts and is excellent in maintenance management property.

As a result of intensive studies on the above problems, the present inventors have completed the present invention by finding that an endless chain excellent in sulfuric acid resistance and mechanical strength can be obtained by using an endless chain made of modified polyphenylene ether.
Specifically, the following sludge scrapers and endless chains.

  The sludge scraping machine of the present invention for solving the above-mentioned problems is a sludge scraping machine for scraping sludge accumulated on the bottom of a sedimentation basin, characterized by comprising an endless chain made of modified polyphenylene ether. Do.

Since the endless chain made of denatured polyphenylene ether is excellent in sulfuric acid resistance, deterioration due to high concentration sulfuric acid can be suppressed. Moreover, since it is excellent also in mechanical strength, the fracture | rupture by tension can also be suppressed.
Therefore, according to the sludge scraping machine of the present invention, even if it is used under conditions where high concentration sulfuric acid comes in contact, such as using a sedimentation tank as a rainwater conditioning tank etc, replacement frequency of parts is low and maintenance It is possible to provide a sludge scraper with excellent manageability.

Furthermore, the present invention is characterized in that the sliding property improvement means is provided in the sliding portion of the endless chain.
The slideability of the endless chain can be enhanced by providing a slideability improving means such as a gap or a spacer in the slide portion of the endless chain. And since the motive power of an endless chain is reduced by improving slidability, the sludge scraper excellent in energy saving property can be provided.

Further, the endless chain of the present invention for solving the above problems is an endless chain used for a sludge scraping machine for scraping sludge deposited on the bottom of a sedimentation basin, characterized in that it is made of denatured polyphenylene ether. Do.
According to the endless chain of the present invention, as described above, it is possible to provide an endless chain excellent in sulfuric acid resistance and mechanical strength. Therefore, when using the existing sludge scraper in the environment which contacts high concentration sulfuric acid, the sludge scraper of this invention can be provided by replacing | exchanging only an endless chain.

  According to the sludge scraping machine of the present invention, since it is provided with an endless chain excellent in sulfuric acid resistance and mechanical strength, the environment where it contacts with high concentration sulfuric acid, for example, when the settling tank is used for rainwater conditioning pond etc. Even when used, the frequency of replacement of parts can be reduced.

It is a schematic explanatory drawing which shows the structure of the sludge scraping machine of the embodiment of this invention. It is a schematic explanatory drawing which shows the structure of the parts of the endless chain of the embodiment of this invention. It is a schematic explanatory drawing which shows the structure at the time of assembling the parts of the endless chain of the embodiment of this invention. It is an enlarged view of the connection part of the endless chain of the embodiment of the present invention. (A) It is a schematic explanatory drawing for demonstrating the means provided with the clearance gap as a slidability improvement means. (B) It is a schematic explanatory drawing which shows another aspect of a means provided with the clearance gap as a slidability improvement means. It is an enlarged view of the connection part of the endless chain of the embodiment of the present invention. (A) A schematic explanatory view showing a structure in which a spacer is provided as a sliding property improving means in a sliding portion formed between the inner surface of the open end of the chain body and the outer surface of the fixed end of the chain body. is there. (B) The sliding portion formed between the outer peripheral surface of the connecting pin and the inner peripheral surface of the connecting pin insertion portion on the fixed end side of the chain body is provided with a spacer as a sliding property improving means It is a schematic explanatory drawing shown.

The sludge scraping machine of the present invention is a sludge scraping machine for scraping sludge deposited on the bottom of a sedimentation basin, and is characterized by including an endless chain made of denatured polyphenylene ether.
Further, the endless chain of the present invention is an endless chain used for a sludge scraping machine for scraping sludge deposited on the bottom of a sedimentation tank and is characterized by being made of denatured polyphenylene ether.

  The modified polyphenylene ether is a generic term for synthetic resin polymer alloys belonging to thermoplastic resins containing polyphenylene ether having an aromatic polyether structure. As resin components other than polyphenylene ether contained in denatured polyphenylene ether, polystyrene resin, impact-resistant polystyrene resin, polyamide resin, polypropylene resin, polyester resin, polyacetal resin, polyphenylene sulfide resin etc. are mentioned, for example.

  Preferred modified polyphenylene ethers are polymer alloys comprising high impact polystyrene resin, polyamide resin, polyester resin, polypropylene resin, and particularly preferred modified polyphenylene ether is a polymer alloy comprising high impact polystyrene resin. The impact-resistant polystyrene resin is a resin obtained by blending or copolymerizing a rubber component with a polystyrene resin.

In addition, the modified polyphenylene ether of the present invention is excellent in sulfuric acid resistance. The sulfuric acid resistance is a substance that is resistant to 10% by mass or more of sulfuric acid, preferably 40% by mass or more, and particularly preferably 90% by mass or more of sulfuric acid.
Here, the resistance to sulfuric acid of denatured polyphenylene ether is evaluated by performing a tensile test after immersing a test piece formed of denatured polyphenylene ether in sulfuric acid of a predetermined concentration for 150 hours. The evaluation method is performed by comparing the tensile strength (maximum tensile stress) of the test pieces before and after the sulfuric acid treatment. Then, when the tensile strength of the test piece after the sulfuric acid treatment is not different from the tensile strength before the sulfuric acid treatment, the modified polyphenylene ether is evaluated as having resistance to sulfuric acid of a predetermined concentration.

  Hereinafter, embodiments of the sludge scraper and endless chain according to the present invention will be described in detail with reference to the drawings. The structures of the sedimentation basin, the sludge scraper and the endless chain described in the embodiment are merely exemplified to describe the sludge scraper and the endless chain according to the present invention, and are limited thereto is not.

[Embodiment]
FIG. 1 is a schematic explanatory view showing the structure of the sludge scraping machine 1 according to the embodiment of the present invention.
As shown in FIG. 1, the sludge scraping machine 1 of the embodiment is installed inside a sedimentation tank 10 such as a sewage treatment plant or a water purification plant.

  The sedimentation tank 10 is horizontally long, and treated water such as sewage is supplied from the left side of FIG. 1. A sludge pit 10b is provided at an end of the pond bottom 10a of the sedimentation area 10 on the treated water supply side, and the sludge pit 10b is provided with a discharge pipe 10c for discharging the sludge to the outside.

  In the vicinity of the water surface 10d in the approximate center of the sedimentation basin 10, a scum discharge device 6 consisting of a scum pipe rotatable about its axis is provided over the entire width of the sedimentation basin 10 in the width direction (vertical direction on the paper) There is. An opening extending in the axial direction is formed on the upper circumferential surface of the scum pipe, and the cross-sectional shape is C-shaped. Then, the scum pipe is rotated counterclockwise in FIG. 1 so that the opening is positioned below the water surface 10 d so as to collect the floating matter (scum) floating on the water surface 10 d, and then the returning operation is repeated.

  The sludge scraping machine 1 is provided with an endless chain 3a which moves circumferentially in the sedimentation tank 10 in the longitudinal direction. A pair of endless chains 3a are installed opposite to each other in the width direction (vertical direction in the drawing) of the sedimentation tank 10, and a flight (scratching blade) extending in the width direction of the sedimentation tank 10 is installed on this pair of endless chains 3a. A plurality of 4 are arranged along the circumferential direction. The flight 4 is attached so as to bridge the pair of endless chains 3 a, and both ends of the flight 4 extend from the endless chain 3 a to the widthwise outer side of the sedimentation basin 10 and near the side walls of the sedimentation basin 10 positioned.

  The endless chain 3a is, as shown in FIG. 1, wound around a driving sprocket 2a and three driven sprockets 2b, and mounted so as to move around in the sedimentation basin 10. Further, an endless chain 3b is wound around a drive sprocket 2a and a motor sprocket 5a provided to the motor 5, and transmits the power of the motor 5 to the endless chain 3a.

  The driving sprocket 2a and one driven sprocket 2b are disposed near the water surface 10d, and move the endless chain 3a hooked therebetween in a substantially horizontal direction along the water surface 10d. Then, the scum floating on the water surface 10 d is scraped toward the above-described scum discharging device 6 by the flight 4 attached to the endless chain 3 a.

  Further, the remaining two driven sprockets 2b are disposed near the pond bottom 10a, and move the endless chain 3a hooked therebetween in a substantially horizontal direction along the pond bottom 10a. Then, the sludge deposited on the pond bottom 10a is scraped into the sludge pit 10b by the flight 4 attached to the endless chain 3a. The sludge collected on the sludge pitch 10b is discharged to the outside of the settling tank 10 from the discharge pipe 10c.

  The schematic explanatory drawing of the components which comprise endless chain 3a, 3b is shown in figure by FIG. The endless chains 3 a and 3 b are constituted by a chain body 31, a connection pin 32 and a connection pin fixing tool 33. In addition, the structure of endless chain 3a, 3b of embodiment is only an example, and is not limited to this. For example, it may be a notch chain or the like in which a notch is formed in the chain body.

  The chain body 31 has a shape in which one end of two substantially elliptical plate members is fixed and the other end is opened. In the open end (hereinafter referred to as "open end"), the distance between the two plate members is formed to expand toward the end, and the two plate members at the open end The distance between them is designed to be greater than the width of the fixed end (hereinafter referred to as "fixed end").

  Further, at both ends of the chain main body 31, connection pin insertion portions 31a, 31b for inserting the connection pins 32 are formed respectively, and further, at one outside end of the open end, engagement of the connection pins 32 is performed. It has four protrusions 31c for locking the portion 32a.

The connecting pin 32 is a cylindrical member having a diameter longer than the width of the open end of the chain body 31 and capable of being inserted into the connecting pin insertion portions 31 a and 31 b of the chain body 31.
Further, at one end of the connection pin 32, an engagement portion 32a having a major axis larger than the hole diameter of the connection pin insertion portion 31a and formed in a substantially rhombus shape is provided. Engage between the four projecting pieces 31c.
On the other hand, the other end of the connecting pin 32 is provided with a fixing portion 32 b formed of a groove into which the substantially C-shaped connecting pin fixing tool 33 can be fitted.

Each part of endless chain 3a, 3b of this invention can be obtained by shape | molding modified polyphenylene ether.
In the endless chains 3a and 3b according to the present invention, it is not necessary to make all parts of the chain body 31, the connecting pin 32, and the connecting pin fixture 33 made of modified polyphenylene ether, but depending on the degree of contact with remaining water. The parts may be selected appropriately and made of denatured polyphenylene ether. The chain body 31 is preferably made of denatured polyphenylene ether because it easily contacts the remaining water.

  Further, neither of the endless chains 3a and 3b needs to be made of modified polyphenylene ether. The endless chain 3a wound around the drive sprocket 2a and the three driven sprockets 2b is preferably made of denatured polyphenylene ether because it easily contacts the remaining water when passing near the pond bottom 10a.

FIG. 3 shows a schematic explanatory view when assembling the parts of the endless chains 3a and 3b.
As illustrated in FIG. 3, the chain body 31 sandwiches the fixed end of another chain body 31 between plate members at the open end, and penetrates the connecting pin insertion portions 31 a and 31 b at each end. The connection pin 32 is inserted. The inserted connection pin 32 is fixed by fitting the substantially C-shaped connection pin fixing tool 33 in the fixing portion 32 b and connects the two chain bodies 31.

  In the endless chains 3a and 3b obtained by connecting a plurality of chain bodies 31, a sliding portion 34a is formed between the inner surface of the open end of the chain body 31 and the outer surface of the fixed end of the chain body 31. The sliding portion 34 b is formed between the outer peripheral surface of the connecting pin 32 and the inner peripheral surface of the connecting pin insertion portion 31 b on the fixed end side of the chain body 31.

Since the modified polyphenylene ether is inferior in slidability as compared with polyacetal, there is a possibility that the movement in the sliding portions 34a and 34b may become hard. Therefore, it is preferable to provide a sliding property improving means on the sliding parts 34a and 34b.
The slidability improving means may be any means as long as the slidability is improved, and examples thereof include a means for providing a gap in the sliding portion and a means for providing a spacer in the sliding portion.
By providing the slidability improving means, the endless chains 3a and 3b move smoothly, and the power can be reduced.

  It is preferable to apply a means for providing a gap in the sliding portion 34 a formed between the inner surface of the open end of the chain body 31 and the outer surface of the fixed end of the chain body 31. According to this means, there are advantages that the number of parts is small and assembly is easy.

On the other hand, in the sliding portion 34b formed between the outer peripheral surface of the connecting pin 32 and the inner peripheral surface of the connecting pin insertion portion 31b on the fixed end side of the chain main body 31, a gap is provided as a sliding property improving means. Even if it is configured, the endless chain is pulled by being brought into contact, and the slidability can not be improved.
Therefore, in the sliding portion 34b, it is preferable to apply a slidability improving means other than the means for providing a gap. For example, the means etc. which provide a spacer in a sliding part are mentioned.

In FIG. 4, a means for providing a gap in the sliding portion 34 a is illustrated as the sliding property improving means. The means for providing a gap means the distance between the inner surfaces of the open end of the chain main body 31 (see “X” in FIG. 4A) and the width of the fixed end of the chain main body 31 (FIG. 4A). Is a means for forming a gap in the sliding portion 34a, which is designed to be larger than “Y”.
Preferably, the distance (X) between the inner surfaces of the open ends of the chain main body 31 is 0.5 mm or more larger than the width (Y) of the fixed end of the chain main body 31, and more preferably 1 mm or more.

  Furthermore, in FIG. 4 (B), in order to provide a gap more reliably, the connection pin 35 provided with one or more steps is illustrated. The connecting pin 35 is provided with step portions 35a and 35b of two stages so as to reduce the diameter in the insertion direction.

  On the other hand, the hole diameter of the two connection pin insertion portions 31a formed at the open end of the chain main body 31 and the hole diameter of the connection pin insertion portion 31b formed at the fixed end are designed according to the diameter of the connection pin 35 It is done. That is, of the connecting pin insertion portion 31a at the open end portion, the hole diameter on the front side in the insertion direction of the connecting pin 35 (see “L” in FIG. 4B), of the connecting pin insertion portion 31b formed at the fixed end The hole diameter (see “M” in FIG. 4B) and the hole diameter at the rear of the connecting pin 35 in the insertion direction of the connecting pin insertion portion 31a at the open end (“N” in FIG. 4B Reference respectively corresponds to the diameter from the fixing portion 32b of the connecting pin 35 to the step 35a, the diameter from the step 35a to the step 35b, and the diameter from the step 35b to the engaging portion 32a.

  Further, the length from the step 35a to the step 35b is designed to be larger than the length of the connecting pin insertion portion 31b formed at the fixed end. Thus, a gap is formed in the sliding portion 34a.

Since tension is applied when the endless chain 3a is used, the open end of the chain body 31 is forced in the closing direction. Therefore, the distance (X) between the inner surfaces of the open end of the chain body 31 may be reduced, and the gap as the slidability improving means may disappear.
As shown in FIG. 4B, by using a connecting pin having one or more steps, a gap is formed in the connecting portion of the chain main body 31 in order to restrict the lateral movement of the open end. It can form more reliably.

In FIG. 5, a means for providing a spacer on the sliding portion is illustrated as a means for improving the slidability.
FIG. 5A shows a configuration in which a spacer 36a is provided on a sliding portion 34a formed between the inner surface of the open end of the chain main body 31 and the outer surface of the fixed end of the chain main body 31. There is.
5B, a spacer 36b is formed on the sliding portion 34b formed between the outer peripheral surface of the connecting pin 32 and the inner peripheral surface of the connecting pin insertion portion 31b on the fixed end side of the chain main body 31. Is shown.

  The spacers 36a and 36b may be made of a material having a slidability higher than that of the modified polyphenylene ethers. The spacer does not have to be a separate member, and a coating of a material having excellent slidability may be formed on the sliding portions 34a and 34b.

  Further, the chain body 31 may be formed of denatured polyphenylene ether excellent in sulfuric acid resistance, and the connection pin 32 may be formed of a material excellent in slidability. In addition, polyamide etc. are mentioned as a material which was more excellent in slidability than denatured polyphenylene ether.

  The sludge scraping machine of the present invention is used, for example, in a settling tank such as a sewage treatment plant, a wastewater treatment plant, or a water purification plant to scrape sludge accumulated on the bottom of a pond. In particular, it is used in an environment where high concentration of sulfuric acid is attached. The environment where high concentration sulfuric acid is attached includes, for example, the case where the water inside the sedimentation tank is used as it is, such as a sedimentation tank used as a rainwater conditioning tank.

  The endless chain of the present invention is used by being attached to the above-mentioned sludge scraper. For example, when using the existing sludge scraping machine as a rainwater regulating pond, the endless chain attached to the existing sludge scraping machine can be replaced with the endless chain of the present invention.

1 Sludge scraping machine, 2a drive sprocket, 2b driven sprocket, 3a, 3b endless chain, 4 flight, 5 motor, 5a motor sprocket, 6 scum discharging device, 10 settling basin, 10a pond bottom, 10b sludge pit, 10c drainage Pipe, 10d water surface, 31 chain body, 31a, 31b connecting pin inserting portion, 31c projecting piece, 32 connecting pin, 32a engaging portion, 32b fixing portion, 33 connecting pin fixing tool, 34a, 34b sliding portion, 35 connecting pin , 35a, 35b steps, 36a, 36b spacers

Claims (3)

It is a sludge scraper that scrapes sludge accumulated on the bottom of a sedimentation basin.
A sludge scraper characterized by comprising an endless chain made of modified polyphenylene ether.   The sludge scraping machine according to claim 1, wherein the endless chain is provided with means for improving slidability at the sliding portion. An endless chain used for a sludge scraper that scrapes sludge deposited on the bottom of a sedimentation basin,
An endless chain characterized by being made of modified polyphenylene ether.

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