JP2005133515A - Cleaning method for sewage facility - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cleaning method for a sewage facility quite economical and excellent in convenience and practical use, in which a blasting material made mostly from sodium bicarbonate is adapted, so that labor and cost in recovery and disposal can be reduced and also that acidification generated by sulfuric acid particular to the sewage facility can be suppressed. <P>SOLUTION: A method for cleaning a concrete section of the sewage facility is to high-pressure jet the blasting material 1 made mainly from sodium bicarbonate to a corroded and deteriorated part of the concrete section corroded by the sulfuric acid, so as to remove, exfoliate or clean the corroded and deteriorated part. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for cleaning sewerage facilities.

  In sewerage facilities, for example, concrete pipes, sulfur circulation occurs due to the activity of sulfate-reducing bacteria and sulfur-oxidizing bacteria starting from sulfate ions in sewage or sludge, and in the gas phase part of sulfuric acid produced from hydrogen sulfide. Corrosion of concrete occurs. Such corrosion of the concrete by sulfuric acid causes damage to the pipe, and damage to the pipe causes ground water and soil contamination due to road collapse and sewage leakage. Therefore, prevention of pipe corrosion is an important issue.

  Therefore, pipes are repaired or renovated by anti-corrosion work or pipe repair work, but before such measures are taken, the surface of pipes must be cleaned and corrosion-degraded parts removed by sulfuric acid. Conventionally, sandblasting has been used for such work.

  In this sandblasting method, a blasting material is mixed with compressed air or high-pressure water and sprayed to remove, peel or clean the corrosion-deteriorated portion.

  By the way, high-hardness silica sand, which has been excellent in that it can physically remove, peel, or wash a corrosion-deteriorated part, has been widely used as a blasting material.

  However, since silica sand is now obligated to be collected as industrial waste, it has a problem that it takes a lot of cost and labor to collect and treat, and it cannot suppress acidification due to generation of sulfuric acid, etc., which is unique to sewer facilities. There was also a problem. On the other hand, it is known that baking soda is used as a blasting material (Patent Document 1), but an example in which it is applied to the removal of a corrosion-degraded portion by sulfuric acid in a sewerage facility has not been known.

JP-A-10-86064

  The present invention employs a blasting material made of baking soda as a raw material, can reduce the time and cost of recovery and treatment, and can suppress acidification due to the generation of sulfuric acid peculiar to sewerage facilities. It provides a method for cleaning sewerage facilities with excellent practicality.

  The gist of the present invention will be described with reference to the accompanying drawings.

  A method for cleaning a concrete part in a sewerage facility, in which a blasting material 1 mainly composed of baking soda is sprayed at a high pressure on a corrosion-degraded part of the concrete part that has been corroded by sulfuric acid, and the corrosion-degraded part is removed, peeled off or washed. This relates to a method for cleaning sewerage facilities.

  Further, in the cleaning method for a sewerage facility according to claim 1, the corrosion deterioration part is a corrosion deterioration part in a concrete pipe, a concrete manhole, a concrete part in a pumping station, a concrete part in a sewage treatment plant, or the like. This relates to a method for cleaning sewerage facilities.

  The sewerage facility cleaning method according to any one of claims 1 and 2, wherein the blast material 1 has a mass-based average particle diameter in the range of 0.1 to 5.0 mm. It concerns the method.

  Moreover, in the washing | cleaning method of the sewer facilities of any one of Claims 1-3, spraying of the blast material 1 concerns on the washing | cleaning method of the sewer facilities characterized by performing by the movable nozzle 3. is there.

  The preferred embodiment of the present invention will be briefly described by showing its effects.

  In the present invention, a blast material 1 containing sodium bicarbonate as a main material is injected at a high pressure into a corrosion deterioration portion of a concrete part of a sewer facility to remove, peel or wash the corrosion deterioration portion.

  The present invention employs a blasting material 1 that is water-soluble and weakly alkaline when dissolved in water as a blasting material 1 that is injected at high pressure into a corrosion-deteriorated part of a sewerage facility. The problem as in the conventional case of using the method is surely solved.

  Specifically, when silica sand is used as the main material of the blast material 1 as in the past, the silica sand does not dissolve in the water, causing a serious trouble due to accumulation of silica sand in the sewerage facilities to be cleaned. Since the possibility of bringing about is very high, it is necessary to collect and treat the used silica sand as industrial waste, and there is a disadvantage that a great deal of cost and labor are required.

  Moreover, since the dispersion of silica sand and water is weakly acidic or neutral, there is a problem that acidification unique to sewerage facilities cannot be mitigated by neutralization.

  In this respect, the baking soda used as the main material of the blasting material 1 of the present invention has been used as a food additive, a pharmaceutical product, and a feed and has been confirmed to be safe, has a high detergency, and is water-soluble. In the sewerage facility to be cleaned, it does not cause accumulation due to stagnation. Furthermore, since the sodium bicarbonate according to the present invention has a low environmental load, the aqueous solution can be discharged into the sea, rivers, and lake closed areas.

  Therefore, the blasting material 1 mainly composed of baking soda according to the present invention does not need to be collected and treated after use, and thus is excellent in convenience and economy.

  Moreover, since the aqueous solution of baking soda and water is weakly alkaline, acidification peculiar to sewerage facilities can be mitigated by neutralization.

  As described above, the present invention provides a method for cleaning sewerage facilities that is extremely practical.

  1 and 2 illustrate a first embodiment of the present invention, which will be described below.

  This embodiment is a case of removing, peeling, or cleaning a corrosion-degraded portion of a concrete part of a sewerage facility, for example, a concrete pipe tank 2 by sulfuric acid, and specifically, a blast material made of baking soda as a raw material. 1 is a case where a nozzle 3 is used to spray high pressure 1 on the corrosion deteriorated portion.

  Furthermore, in the sewerage facilities, a sulfur cycle in which the activity of sulfate-reducing bacteria and sulfur-oxidizing bacteria starting from sulfate ions in the sewage or sludge is excellent, and the sulfuric acid produced from hydrogen sulfide produces concrete in the gas phase. Corrosion occurs.

  The nozzle 3 is provided on a movable movable body 5 having a cylindrical shape, and is connected to a supply source (not shown) that supplies the blast material 1 at a high pressure via a hose 4.

  A support portion 7 is provided at a side portion of the moving body 5, and a wheel 6 is provided at the tip of the support portion 7. The nozzle 3 and the hose 4 of the moving body 5 are always arranged at the center of the pipe 2 by the support portion 7 and the wheel 6, and the moving body 5 is moved back and forth by the support portion 7 and the wheel 6. It is configured to be movable in the direction.

  Moreover, the said support part 7 is comprised so that attachment or detachment or expansion / contraction is possible so that it can be used with the pipe 2 of various pipe diameters. Specifically, in the case of the pipe 2 having a pipe diameter of 150 mm or more, the movable body 5 can be used by attaching / detaching / stretching the support portion 7 as appropriate. The total length of the moving body 5 is about 500 mm to 1000 mm so that it can be easily inserted into the tube tube 2 through a human hole having a tube diameter of 600 mm.

  The moving body 5 is moved by connecting a wire 8 to the distal end portion of the moving body 5 and pulling the wire 8 with a winch. For this reason, unlike a self-propelled robot (automatic device), it does not stop halfway due to a failure or the like. Even if the moving body 5 breaks down in the tube 2, the moving body 5 can be moved forward or backward by pulling the wire 8 or the hose 4. Also, the mobile body 5 can be collected.

  In addition, when using the said mobile body 5 for a human hole, it works so that it may suspend from a ground part.

  The injection of the blast material 1 will be described.

  The blast material 1 is sprayed from the nozzle 3 in a radial direction so as to be sprayed on the entire inner surface of the tube pipe 2, and the nozzle 3 is moved in the length direction of the tube pipe 2 by the moving body 5. The pipe 2 is removed, peeled off or washed away from the corrosion deteriorated portion.

  When the blast material 1 is supplied in a mixture with compressed air, the blast material 1 stored in a tank is mixed with air compressed by a compressor and supplied at a pressure of 0.8 to several MPa or less.

  In addition, when mixed and supplied with high-pressure water, the blast material 1 stored in the tank is mixed with high-pressure water ejected from a high-pressure washing device and supplied at a pressure of 400 MPa or less.

  In addition, when the sprayed blast material 1 is scattered or dust is a problem, or when it is necessary to flush the hanger or the like due to the injection of the blast material 1 to the downstream side, water 9 is injected from the moving body 5. It is good also as such a structure. In this case, the moving body 5 can be moved using the pressure of the water 9 (self-propelled moving body 5).

  Since a supply source such as a tank for storing the blasting material 1 and a supply device is generally provided outside the pipe 2, the moving body 5 is used to supply the inside of the pipe 2. When the spraying operation is performed over a long distance, the moving body 5 is far away from the supply source, the jet pressure at which the blasting material 1 is jetted from the nozzle 3 is lowered, and the effect of cleaning and suspension is lowered. Therefore, if the moving body 5 is configured to incorporate or connect the supply portion of the blast material 1, the transport distance of the blast material 1 is shortened, and a reduction in the jet pressure from the nozzle 3 can be prevented.

  Next, the blast material 1 of the present embodiment will be described.

  The blasting material 1 is superior in safety, has a low environmental load, is water-soluble and can be discharged into the environment, dissolves in water to become weakly alkaline, and contains sodium bicarbonate having a bacteriostatic action and a deodorizing action as a main material. .

  As the blast material 1 containing sodium bicarbonate as a main material, those having a mass-based average particle diameter of 0.1 to 5.0 mm are adopted as a result of experiments. When the average particle diameter is 0.1 mm or less, it is too fine to obtain a sufficient blasting effect, so that it is not suitable. When the average particle diameter is 5.0 mm or more, a large amount of power is required for conveying the blast material 1 and the nozzle 3 This is not suitable because there is a risk of blocking, and the equipment for cleaning can be large.

  This average particle size is a value measured by an automatic measuring device SEISHIN-ROBOTSIFTER-RPS-95 (Seishin Enterprise Co., Ltd.) using a JIS standard sieve, and is an average particle size in mass-based particle size distribution measurement.

  Next, the concrete part of a present Example is demonstrated.

  The concrete part of the present embodiment is a concrete part such as a reinforced concrete pipe 2 or a human hole, a pumping station, a treatment plant, etc. in which concrete corrosion is caused by sulfuric acid.

  Since the present embodiment is configured as described above, the following operational effects are obtained.

  By using the movable cylindrical moving body 5, the blast material 1 can be injected evenly onto the inner surface of the tube 2 or the like. Therefore, it is possible to satisfactorily remove, peel or wash the corrosion-deteriorated portion such as the pipe shell 2 and expose the sound concrete.

  In addition, the physical cleaning effect using baking soda particles enables effective cleaning without spraying at a very high pressure, enables operation at a relatively safe spraying pressure, and is water-soluble and environmentally friendly. Since it is low and there is no need for collection and processing after use, it is excellent in convenience and economy.

  Furthermore, acidification peculiar to sewerage facilities can be neutralized by baking soda, and bacteriostatic and deodorizing effects in sewerage facilities having a poor work environment can be exhibited due to bacteria and bad odors, thereby improving the work environment.

  Next, an experimental example for confirming the effect of the first embodiment will be described.

  7N and 15N test pieces (49 x 49 cm) were manufactured assuming the compressive strength of the concrete that had deteriorated due to corrosion in sewerage facilities. For this test piece, baking soda with an average particle diameter of 250 μm was used as the blasting material 1 and Eco Shower SB400 (Eco Global Laboratories Co., Ltd.), which is a blasting material jet, and 0.5 MPa, 0.7 MPa as the blasting media transport medium. Table 1 shows the results of injection with a compressed amount of 2.5 kg / min.

  From this result, it was confirmed that the concrete surface could be scraped off in the concrete corrosion deteriorated part of the sewerage facility. It was also confirmed that the concrete surface could not be scraped off when only compressed air of 0.5 MPa and 0.7 MPa was sprayed onto 7N and 15N test pieces (49 × 49 cm), respectively.

It is explanatory drawing of the use condition of the Example of this invention. It is explanatory drawing of the use condition of the Example of this invention.

Explanation of symbols

1 Blasting material 2 Pipe pipe 3 Nozzle

Claims (4)

  A method for cleaning a concrete part in a sewerage facility, in which a blasting material mainly composed of baking soda is jetted onto a corrosion-degraded part corroded by sulfuric acid in the concrete part to remove, peel or wash the corrosion-degraded part. A method for cleaning a sewerage facility, characterized by:   2. The method for cleaning sewerage facilities according to claim 1, wherein the corrosion deterioration part is a corrosion deterioration part in a concrete pipe, a concrete manhole, a concrete part in a pumping station, a concrete part in a sewage treatment plant, or the like. A method for cleaning sewerage facilities.   The method for cleaning a sewerage facility according to any one of claims 1 and 2, wherein the blast material has a mass-based average particle diameter in the range of 0.1 to 5.0 mm. The method for cleaning a sewerage facility according to any one of claims 1 to 3, wherein the blast material is sprayed by a movable nozzle.

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