JP2003147598A - Device for removing precipitation on liquid contact surface in metallic mechanical structure installed underwater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for removing precipitation on a liquid contact surface in a metallic mechanical structure installed underwater, the device that needs no large-scale equipment, that is safe and excellent in operability because of complete unmanned automation, and that enables precipitation removing effect to be obtained on an energy-saving, low-cost and everlasting basis. SOLUTION: A positive output terminal 5 of a variable constant voltage DC power unit 4 is connected to an electrically conductive air lead-through part 2 in an underwater metallic mechanical structure 1 (structure) installed in an electrolyte 7 in a water tank; a negative output terminal 6 is connected to a negative electrode 3 installed in the electrolyte 7 oppositely in a non-contact state with the structure 1; the electric recovery circuit of the variable constant voltage DC power unit 4 is formed through the electrolyte 7 by voltage application; and thus, a weak current is designed to flow onto the surface of the liquid contact part of the structure 1.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for removing deposits generated on the surface of a wetted part of a metal mechanical structure such as an underwater ponder which is installed and used in water. is there. 2. Description of the Related Art A large amount of concrete curing water or mineral-based dissolved substances flows into a dam construction site using a submersible pump, a construction site such as a well casing, or a pumping water such as hot spring water. If calcium carbonate, magnesium carbonate, or magnesium sulfate precipitates and grows as a film on the liquid contact part of the submersible pump for drainage, an impeller lock phenomenon occurs, and excessive current flows to the motor, which may lead to a burnout accident. There is. Further, if the heat is deposited on the outer surface of the motor and grows, the heat generated by the motor cannot be sufficiently dissipated into the air or water, causing a heat storage phenomenon, which may lead to a burnout accident. In such a situation, a technical worker must rush to the site to stop supplying power to the submersible pump, raise the submersible pump, and install a new alternative pump. In addition, submersible pumps are usually installed as a set of two pumps, a main pump and a backup pump. If any abnormality occurs in the main pump and the pump stops, the backup pump immediately starts operation and continues draining. However, in the case of an abnormality caused by deposits adhering to the pump as described above, since almost two units proceed simultaneously and cause an abnormality,
It is also assumed that neither pump is drained at the installation site, and that the surroundings of the site are flooded. In addition, prior to carrying out repair and maintenance of broken submersible pumps, etc., a great deal of effort and time is being spent on removing strongly precipitated calcium carbonate, magnesium carbonate, magnesium sulfate, etc. Therefore, the maintenance and repair cost is increased. [0004] Conventional methods for removing precipitated calcium carbonate, magnesium carbonate, magnesium sulfide, and the like include a method of removing kerosene by sandblasting, a method of cleaning and removing by high-pressure water, and the like.
This is a cutting and removing method using a rotating brush, but each has a large disadvantage. [0005] The method for removing kerosene by sandblasting or the like requires a large-scale facility in a maintenance shop, which is expensive. Since the surface of the pump etc. is scraped off by blasting, the power cable, packing, resin material, etc. must be covered with a cover so as not to come into direct contact with the blast particles, and also precipitated on the inner surface of the liquid contact part For calcium carbonate and magnesium carbonate, the equipment must be disassembled for implementation, and workability is poor. Equipment for collecting the debris after blasting is required. And the like. [0006] The cleaning and removing method using high-pressure water requires large-scale equipment in a maintenance shop, and is expensive. Since the surface of the pump etc. is shaved off by high-pressure water, the power cable, packing part, resin material part, etc. must be covered and carried out. In other words, the equipment must be disassembled and implemented, resulting in poor workability. Equipment for treating a large amount of wastewater after washing is required. And the like. [0007] In the cutting and removing method using the rotating brush, the operation is performed for a long time by hand and always involves danger. For calcium carbonate and magnesium carbonate precipitated on the inner surface of the liquid-contacting part, the apparatus must be disassembled and performed, resulting in poor workability. Equipment for collecting the removed debris after cutting is required. And the like. An object of the present invention is to provide a safe and excellent workability by completely unattended automation without requiring a large-scale facility, and to supply a weak DC current without using any power. An object of the present invention is to provide an apparatus for removing deposits on the surface of a liquid-contacting part of a metal machine structure installed in water, which realizes significant power saving and energy saving, and has a low-cost and permanent deposit removing effect. According to the present invention, in the apparatus for removing deposits on the surface of a wetted part of a metal mechanical structure installed underwater, the positive output terminal of the variable constant voltage DC power supply is connected to the electrolyte solution in the water tank. Connect to the conductive aerial outlet of the installed underwater metal machine structure and connect the negative output terminal of the variable constant voltage DC power supply to the electrolyte solution in a non-contact manner with the underwater metal machine structure. An electric circuit of a variable constant voltage DC power supply is formed through the electrolytic solution by applying a voltage, connected to the opposite negative electrode, so that a weak current flows on the surface of the liquid contact part of the metal mechanical structure installed underwater. Configured. The electric circuit of the variable constant-voltage DC power supply is formed through the electrolytic solution by the application of a voltage, and a weak current flows on the surface of the liquid contacting part of the metal machine structure installed in the water, and is activated by the weak current. With the slight dissolution of the wetted surface, calcium carbonate, magnesium carbonate, magnesium sulfide, and the like, which have been deposited on the wetted surface, gradually dissolve from the surface. An embodiment will be described below with reference to the drawings. Reference numeral 1 denotes a submersible metal mechanical structure, such as a submersible pump, from which deposits are to be removed, and is installed in an electrolyte solution 7 in a water tank. Reference numeral 2 denotes a conductive air outlet of the underwater metal structure 1, which corresponds to a discharge pipe of the submersible pump. Reference numeral 3 denotes a negative electrode, which is opposed to the underwater-installed metal mechanical structure 1 in the electrolyte solution 7 in the water tank. Reference numeral 4 denotes a variable constant-voltage DC power supply. A positive output terminal 5 is connected to the conductive air outlet 2 of the underwater metal machine structure 1, and a negative output terminal 6 is connected to the negative electrode 3. . Note that the electrolyte solution 7 in the water tank may be, for example, a saline solution diluted to such an extent that the metal does not corrode or the like. When a voltage is applied by the above-described configuration, an electric circuit of the variable constant-voltage DC power supply 4 is formed via the electrolyte solution 7, and a weak current flows on the surface of the liquid-contacting portion of the underwater-installed metal mechanical structure 1. With the slight dissolution of the liquid contact surface activated by the weak current, calcium carbonate, magnesium carbonate, etc., deposited on the surface of the liquid contact part, gradually dissolve from the surface, and finally easily with tap water. The precipitate can be removed only by rinsing. In this way, the surface of the wetted portion of the underwater-installed metal mechanical structure 1 such as a submersible pump can be restored to a clean state as needed. Then, not only the function of removing the generated precipitates, but also the function of preventing the precipitations work. According to the present invention, there is no need for large-scale equipment, complete automation is safe and excellent in workability, and only a weak DC current is supplied without using any power. Achieves low power consumption and energy saving, low cost and permanent deposit removal effect, and uses diluted saline solution as electrolyte solution. There is also the advantage that no adverse effects occur.

[Brief description of the drawings] FIG. 1 is an explanatory diagram showing a configuration of the present invention. [Explanation of symbols] 1 Underwater metal structure 2 Air outlet 3 Negative electrode 4 Variable constant voltage DC power supply 5 Positive output terminal 6 Negative output terminal 7 Electrolyte solution

Claims (1)

Claims: 1. A positive output terminal of a variable constant voltage DC power supply is connected to a conductive aerial outlet of an underwater metal mechanical structure installed in an electrolyte solution in a water tank. Then, connect the minus side output terminal of the variable constant voltage DC source device to the minus side electrode that is installed in the electrolyte solution in a non-contact manner with the underwater metal mechanical structure, and change the voltage through the electrolyte solution by applying voltage. The electric circuit of the constant-voltage DC power supply is formed, and a weak current flows on the surface of the liquid-contacting part of the metal machine structure to be installed underwater. Precipitate removal equipment.