Protection methods

Abstract

To provide a protection method that can be applied at a site where equipment is operated using general-purpose materials.SOLUTION: A protection method according to the present invention for an article in an environment where scale may adhere, comprises applying grease to a portion to be protected.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for protecting articles in an environment where scaling may occur. [Background technology]

[0002] In facilities such as leachate treatment facilities that treat leachate discharged from final disposal sites for waste such as incineration ash, the formation of scale at points where the liquid comes into contact is a problem. Scale is typically formed by the deposition of inorganic salt compounds such as calcium on the surface of the facility, and can adhere firmly to the surface of the facility, making it difficult to remove.

[0003] In view of this problem, technologies for facilitating scale removal have been studied. For example, Japanese Patent No. 6687776 (Patent Document 1) discloses a technology for applying a coating containing epoxy resin to areas where scale may form. Furthermore, Japanese Patent Laid-Open Publication No. 2011-156465 (Patent Document 2) discloses a technology for arranging an adhesion-suppressing member made of fluororesin or the like in areas where scale may form. When the technologies of Patent Documents 1 and 2 are applied, scale removal becomes easier than when they are not applied. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6687776 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-156465 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the technology of Patent Document 1 requires that a special coating material be applied to the parts to be protected, and that workers engaged in maintaining the equipment must carry such coating material.Furthermore, the technology of Patent Document 2 requires that a lining such as a fluororesin be applied to the pipes, etc., at the time of manufacturing, making it difficult to apply to equipment that is currently in operation.

[0006] Therefore, it is necessary to realize a protection method that uses general-purpose materials and can be applied to facilities that are currently in operation. [Means for solving the problem]

[0007] The protection method according to the present invention comprises: Contains calcium attached to items that come into contact with water containing calcium ions scale To facilitate the removal of 1. A method for protecting an article, comprising: The above-mentioned item The part to be protected The consistency measured in accordance with JIS K 2220:2013 is 2 or more, and the water wash resistance measured in accordance with JIS K 2220:2013 at 38°C for 1 hour is 3.0% or less. The method is characterized by including applying grease.

[0008] The present inventors discovered that applying grease to areas where scale may accumulate facilitates the removal of scale, and thus completed the present invention. Such grease is widely used for its intended purpose, such as lubricating drive units, in this type of equipment. In other words, the above configuration makes it possible to realize a protection method that uses general-purpose materials and is applicable to equipment currently in operation. Furthermore, since the parts to be protected are typically in an environment where they are exposed to running water, and there is a risk that the applied grease will wash away, if a grease with a consistency of 2 or more and a water washout resistance of 3.0% or less at 38°C for 1 hour is used, the applied grease is less likely to wash away, and therefore the protective effect is more likely to be maintained.

[0009] Preferred embodiments of the present invention will be described below, but the scope of the present invention is not limited to the preferred embodiments described below.

[0014] In one aspect of the protection method according to the present invention, the grease is preferably a soap-based grease.

[0015] Soap-based greases are often carried for normal lubrication by workers who perform maintenance work on items in environments where scale may form, so the protective method of the present invention is relatively easy to implement using soap-based greases.

[0016] In one aspect of the protection method according to the present invention, the grease is preferably a lithium soap-based grease.

[0017] Lithium soap grease has excellent water resistance and is therefore particularly suitable as the grease to be used in the present invention.

[0018] Further features and advantages of the present invention will become more apparent from the following description of exemplary and non-limiting embodiments, which is given with reference to the drawings. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a schematic diagram illustrating the mechanism of action of a protection method according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0020] An embodiment of the protection method according to the present invention will be described with reference to the drawings. In the following, an example will be described in which the protection method according to the present invention is applied to a method for protecting a water tank, piping, equipment, meters, etc. installed in a leachate treatment facility at a final disposal site for municipal waste.

[0021] [Protected Subjects] The protection method according to this embodiment is a method for protecting an article in an environment where scale may form and facilitating the removal of scale accumulated on the article. A leachate treatment facility, to which this embodiment is applied, is an example of an environment where scale may form. In a leachate treatment facility, calcium ions contained in the leachate precipitate as calcium carbonate to form scale. Other examples of environments where scale may form include cooling water circulation facilities, geothermal power generation facilities, salt production facilities, and wastewater treatment facilities in food factories.

[0022] The items to be protected (hereinafter referred to as "target items") are not limited to items that come into contact with leachate in leachate treatment equipment, but typical examples include water tanks, valves, piping, equipment, and meters. Examples of equipment include pumps (impellers, casings, shafts) and agitators, while examples of meters include water level gauges, thermometers, flow meters, and pH meters. Furthermore, the parts to be protected (hereinafter referred to as "target parts") are all or part of the parts of the target items that come into contact with leachate.

[0023] The material of the target object and target portion is not particularly limited, and may be, for example, metal, resin, concrete, or the like.

[0024] [Grease] The grease used in the protection method of the present invention can be any commercially available grease. However, if a grease with a consistency of 2 or higher as measured in accordance with JIS K 2220:2013 is used, the grease is less likely to wash away even when leachate flows through the target part, and the protective effect is more likely to last longer. It is also preferable to use a grease with a water washout resistance of 3.0% or less as measured in accordance with JIS K 2220:2013 at 38°C for 1 hour, as this can prevent the grease from washing away. Additionally, it is preferable that the grease does not liquefy or solidify in the environment in which the target part is placed.

[0025] Suitable greases include soap-based greases such as aluminum soap grease, lithium soap grease, calcium complex grease, aluminum complex grease, and lithium complex grease, as well as non-soap-based greases such as polyurea grease, bentonite grease, polytetrafluoroethylene grease, and carbon black grease. Among these, soap-based greases are often carried for normal lubrication by workers performing maintenance work on items in environments where scale may form. Therefore, implementing the protection method according to this embodiment using soap-based greases is relatively easy because it does not require workers to carry additional tools. Furthermore, lithium soap-based greases are particularly preferred due to their excellent water resistance.

[0026] [Protection method] The protection method according to this embodiment includes applying grease to the target part. The application method is not particularly limited, and known methods such as hand application, brush application, spray application, and immersion can be used. Furthermore, the frequency of applying grease is not particularly limited. For example, if the target part is regularly cleaned to remove scale, it is preferable to apply grease each time the cleaning is performed.

[0027] After the grease is applied to the target part, the target is put into normal operation. During operation, scale buildup is observed on the target part, etc. However, the scale adhering to the target part protected by the protection method according to this embodiment can be easily peeled off and removed at the boundary of the grease-applied surface by merely applying manual blows with a hammer or the like.

[0028] Generally, when scale adheres to equipment, it adheres firmly to the surface of the equipment. Furthermore, scale is a hard substance whose main component is calcium carbonate, and it is generally difficult to destroy it with human strength. Therefore, when attempting to remove the scale, whether to destroy the adhesion between the equipment surface and the scale or to destroy the scale itself, a large amount of force is required, making it extremely difficult to remove the scale.

[0029] On the other hand, in the target part 1 (FIG. 1) protected by the protection method according to this embodiment, the scale 2 does not adhere directly to the target part 1, but rather adheres via the grease 3. Therefore, when an impact is applied to the scale 2, the layer of the grease 3 is destroyed, and part of the grease 3, together with the scale 2, comes off from the target part.

[0030] Although the mechanism behind the phenomenon in which scale 2 and grease 3 separate together when scale 2 is struck is unclear, the inventors believe that the thixotropy of grease 3 contributes to this phenomenon. Under normal operating conditions, such as when leachate is present, no shear stress is applied to grease 3 sufficient to reduce its viscosity. On the other hand, when scale 2 is struck, it is believed that shear stress is applied to grease 3 sufficient to reduce its viscosity. This decrease in viscosity makes it impossible for grease 3 to maintain adhesion to the target area, which is thought to be why scale 2 and grease 3 separate together when scale 2 is struck.

[0031] In this way, by applying grease to the target area and providing a portion that is likely to break after scale has adhered, removal of the scale is made easier.

[0032] Other Embodiments Regarding other configurations, it should be understood that the embodiments disclosed in this specification are illustrative in all respects and that the scope of the present invention is not limited thereby. Those skilled in the art will easily understand that appropriate modifications are possible without departing from the spirit of the present invention. Therefore, other embodiments modified without departing from the spirit of the present invention are naturally included in the scope of the present invention. [Example]

[0033] [Object] The target object was the impeller of a lifting pump installed in a reaction tank in a leachate treatment facility that includes a reaction tank in which the pH of the water to be treated is adjusted to 9 to 11 and sodium carbonate is added, a mixing tank in which a coagulant is further added to the water to be treated that has passed through the reaction tank, a coagulation tank in which a polymer is further added to the water to be treated that has passed through the mixing tank, a coagulation sedimentation tank in which flocs contained in the water to be treated that has passed through the coagulation tank are settled and separated, and a neutralization tank in which acid is added to the water to be treated from which flocs have been removed in the coagulation sedimentation tank to neutralize it.

[0034] [Example] Lithium soap grease with a consistency of 2 was applied to the impeller by brushing. The greased impeller was then assembled into a water pump, and the pump was operated under normal operating conditions for 90 to 180 days. The pump was then disassembled, and an attempt was made to remove the scale that had adhered to the impeller. The scale was successfully removed by hitting it with a hammer.

[0035] Comparative Example In the same leachate treatment facility as in the example, the pumping pump was operated normally without applying grease to the impeller. After 90 to 180 days of operation, the pumping pump was disassembled and attempts were made to remove the scale that had adhered to the impeller. However, the scale could not be removed by hitting it with a hammer. To remove the scale, it was necessary to break it down using a chisel.

[0036] 〔result〕 Compared to the comparative example, the scale could be removed more easily in the example. [Industrial Applicability]

[0037] The present invention can be used as a method for protecting equipment, etc. in, for example, leachate treatment facilities. [Explanation of symbols]

[0038] 1 Target area 2. Scale 3. Grease

Claims

1. A method for protecting an article that comes into contact with water containing calcium ions, in order to facilitate the removal of calcium-containing scale adhering to the article, the method comprising applying, to the part of the article to be protected, grease having a consistency of 2 or more as measured in accordance with JIS K 2220:2013 and a water washout resistance of 3.0% or less as measured in accordance with JIS K 2220:2013 at 38°C for 1 hour.

2. 2. The method of claim 1, wherein the grease is a soap-based grease.

3. 3. The method of claim 2, wherein the grease is a lithium soap-based grease.

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