JPS58110391A - Corrosion preventing method and device for hold bottom - Google Patents

Abstract

PURPOSE:To prevent the corrosion at the bottom of the hold due to the coal powder dust and the water stored at the bottom of the hold,by ejecting the clean water or the mixture with a neutral liquid through an injection port at the lower section of the hold wall, after loading the coal in the hold, then discharging through a discharge port at the lower section of the hold. CONSTITUTION:After loading the coal 2 in a hold 1, clean water or the mixture with a neutral liquid is ejected through an ejecting port 6 at the lower section of the hold wall 4, then discharged through a discharge port 7 provided through a hold bottom wall facing with the ejecting port 6 to wash the sulfaric acid component produced at the lower portion of the loaded coal thus to prevent the corrosion at the lower portion of the hold. Said sulfaric acid component is produced particularly at the lower portion of the coal through the combination of the clean water to be sprayed as the countermeasure against the dust and the ion in the coal when loading the coal, and it can be washed when ejecting the clean water or the alkali neutral water such as the lime liquid and discharging.

Description

[Detailed description of the invention] The present invention has the ability to prevent corrosion at the bottom of a ship's hold (1) Regarding equipment.

When loading and transporting coal on a coal ram carrier, the coal is misted or sprayed with water to prevent dust. Therefore, after loading is completed, water containing organic matter contained in the coal accumulates at the bottom of the hold. If the coal contains sulfur, the sulfur content dissolves into the water collected at the bottom of the hold and becomes a sulfuric acid solution, and this sulfuric acid solution corrodes the bottom of the hold. Usually, a paint is applied to the bottom of the hold, but this paint is sensitive to Vi sulfuric acid solution and cannot prevent corrosion.

Therefore, the present invention solves this problem by providing a chest at the bottom of the hold.
The proposed corrosion prevention method is characterized by the fact that after coal is loaded into the hold, fresh water or a mixture of fresh water and neutralizing liquid is poured into the bottom of the hold from an appropriate injection port at the bottom of the hold wall. is injected and drained from a drain provided at or near the bottom of the hold wall opposite to the above-mentioned injection [1]. According to this configuration, the bottom of the hold is spread over tn* between the fresh water and the neutralizing liquid. The bottom of the cargo hold will not be eroded by sulfuric acid disease (2) as it was in the past, as it will be cleaned by the mixed sand. The feature is that an injection port is installed at the bottom of a suitable hold wall to spray a mixture of dripping Wf water and Nakamoto 1 liquid toward the bottom of the vessel. A fresh water tank and a neutralizing liquid tank are provided, and a drain is provided near the lower part of the hold wall opposite to the above-mentioned jet 1.
] A sulfuric acid concentration detector is installed in the drainage path that communicates with the water inlet. According to this configuration, based on the detected value of the sulfuric acid concentration detector, the bottom of the hold is treated with fresh water! The mixed solution allows for efficient cleaning and allows you to know when the concentration of the sulfuric acid solution has exceeded the standard, so there is no lack of cleaning and there is no need to waste the cleaning solution. You can do it without any problems.

An embodiment of the present invention will be described below with reference to the drawings. (1
) The ship η-1 (3) loaded with tri coal (2) had a double bottom, (4) and (5) transverse bulkheads, ((+) &j "a part of one transverse bulkhead (4) Injection ports (5 in this embodiment) are provided at appropriate intervals along the transverse force direction of the hull, (7) is the other transverse bulkhead (5) of the double bottom (3) (3) Several drainage ports (three in this example) are provided at intervals along the transverse direction of the hull near the hull, (8> l-1: located in the stern engine room or pump room, etc.). The fresh water tank installed, (9) Kekoura I (the first pipe connecting the tank (8) and each of the above injection ports (6), (Ill l'i r3 'J's I Ff pipe (
(1) is a neutralizing liquid tank for storing an alkaline neutralizing liquid such as lime liquid, which is disposed on the deck; A second pipe that connects the liquid tank (11) and a part of the first pipe (9) on the downstream side of the first pump UL; aυ is the bilge well installed under the double bottom (3), OQt/i is the vJ3 piping that connects the pilsiquel and each drain port (7), and 0'I) is the bilge well (extending from lO to the outside of the ship). 4th piping, (18
) is a sulfuric acid concentration detector interposed in the fourth pipe Uθ,
(1 Special i4 A control device attached to the detector (18), which compares the set value signal from the sulfuric acid concentration detector (old detection value and setting equipment 1 not lowered). If the result of the calculation and detection is larger, the first pump (11) is activated or the solenoid valve (14) is opened. (4) v; 4 pipes (1'θ concentrated sulfuric acid 1 (detector (
This is a second bonzo interposed at a location downstream of the flat.

- The entire cleaning procedure for the double bottom (3) will be explained based on the configuration described in F. After loading the coal (2), operate the second pump without removing it and discharge the water accumulated in the lower part of the hold (1) to the outside of the ship via the drain port (7) and the fourth pipe (17). At this time, the sulfuric acid concentration detector (1) is used to detect the sulfuric acid concentration in the water, and the above detector (2) is detected in
When the detected value output is compared with the set value signal from the setting device, and the detected value output is smaller than the set value, it is said that there is almost no ion content in the water that was flowing in the above ship hold (mark 1). As a result, there was no ship to clean.

Therefore, it is sufficient to completely stop the operation of the second pump 9j. Next, when the detected value output is larger than the set value signal and the difference is smaller than a predetermined reference flffl, only the first pump is operated.

As a result, the dripping water in the fresh water tank (8) is transferred to the first pipe (9).
) is injected from the injection port (6) onto the double bottom (3), and the thin sulfurized liquid on the bottom (3) is washed away. It's also big and only(
5) When the difference is larger than the reference value, the first pump (1
0 and open the solenoid valve u4).

Then, the middle tlI isthmus in the neutralizing liquid tank θυ is mixed with fresh water, and the mixed liquid is injected from jet n (6) onto the double bottom (3), and the concentrated sulfuric acid solution on the double bottom (3) is is washed away. Note that the opening degree of the electromagnetic valve u4) is adjusted appropriately based on the detected value, and thereby the mixing ratio of the dripping water and the medium 1:+1 liquid is adjusted as appropriate. - When the detected value output and the set value output match after cleaning as described in h. ) should be stopped.

As described above, according to the anti-corrosion method for the bottom of a cargo hold of the present invention, the bottom surface of the cargo hold is washed with fresh water or a mixture of fresh water and a neutralizing solution, and unlike the conventional method, the bottom surface of the cargo hold is not corroded by the JMi acidic solution. It will not be done.

Furthermore, according to the corrosion prevention device at the bottom of the cargo hold, the bottom surface of the cargo hold can be efficiently cleaned with fresh water or a mixture of dripping water and neutralizing solution based on the detected value of the sulfuric acid concentration detector, and the concentration of the sulfuric acid solution can be reduced. Since it is possible to know clearly when the level has fallen below the standard (6), insufficient washing will not occur, and the washing solution will not be wasted.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a schematic blood diagram of the edge 19r, and FIG. 2 is a schematic perspective view of Vi. (1)...Ship bar, (2)...Lime, (3)...Bottom, (4) (5)...Horizontal bulkhead, (6)...Injection port, (7 )...Drain port, (8)...Water tank, (
1 (夛...first pump, (1υ...neutralizing liquid tank,
(1 beauty...Electromagnetic pulp, (18)...4+A+, acid concentration detector, (In...control device, Kan...2nd Boshibu J1! Omorimoto) Hiroshi Atsushi (7)

Claims (1)

[Scope of Claims] 1. After loading the coal into the Japanese warehouse, spray one shot of fresh water or a mixture of fresh water and neutralizing liquid onto the bottom of the cargo hold from an appropriate injection port at the bottom of the cargo hold wall, facing the injection port. A method for treating corrosion at the bottom of a cargo hold, which is characterized by draining water from a drainage hole provided at or near the lower part of the cargo hold wall. 2. An injection port for injecting fresh water or a mixture of fresh water and neutralizing liquid toward the bottom of the hold is provided at the bottom of a suitable hold wall, and a fresh water tank and a neutralizing liquid tank are connected to the injection port. Corrosion at the bottom of the hold, which is characterized by providing a drainage port in the vicinity of the hold wall F section facing the injection port, and installing a sulfuric acid concentration detector in the drainage path communicating with the drainage port. When 1F device ift.