JP2569000B2 - Cleaning method for tanks of chemical tankers - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cleaning a tank in a chemical tanker having a plurality of tanks.

2. Description of the Related Art Chemical tankers are mainly ships that transport chemicals by sea, and the range of chemicals and raw materials handled may vary widely. When the cargo changes or when transferring to a high-grade, high-purity product, it is necessary to wash the tank and completely remove the residual liquid. Great care must be taken to prevent damage to the cargo due to contamination or unexpected chemical changes or alterations. Therefore, for a chemical tanker, the most troublesome task is to wash the tank rather than to unload and load the cargo.

On the other hand, when handling oils such as crude oil, heavy oil, light oil, volatile oil, asphalt, etc.
The cleaning process is also simple. As oil tanker cleaning techniques, for example, Japanese Utility Model Laid-Open No. 57-135000 and Japanese Patent Laid-Open No. 60-15290
The publication discloses an automatic washing machine capable of processing a hold and a deck with one washing machine and a man-machine conversation type washing machine using a control computer and a CRT with a keyboard.

However, in the chemical tanker, a worker has conventionally entered the hull and performed cleaning work mainly by manual labor. Needless to say, a washing machine having excellent work efficiency has been developed, and the labor involved in the washing work has been reduced, and the working time has been shortened. However, securing labor for cleaning the tanks imposes a sarcastic burden on the marine industry, which is forced to save labor, over labor costs, as well as enormous costs. And, if the storm continues, it will fall into a situation where cleaning of the hull cannot be entrusted.

By the way, the cargo handled by chemical tankers contains many chemicals that may cause fire or explosion and chemicals that are harmful to livestock. From the viewpoint of work safety, it is necessary to rely on complete mechanical operation instead of manual labor. Therefore, it is preferable that the hull can be cleaned by remote control in order to avoid the danger of fire and burns, and that the cleaning process should be performed by automation and unmanned operation so as not to inhale toxic gas. I can say.

An object of the present invention is to provide a new cleaning system which is automatically and remotely operated as a method for cleaning a tank in a chemical tanker.

It is another object of the present invention to provide a new cleaning system that enables remote operation to perform the cleaning operation of the hull in parallel with the ship maneuvering operation in order to ensure the safety of the cleaning process.

Thus, in a chemical tanker having a plurality of tanks, a system that can select a tank requiring cleaning treatment based on a loading and transport plan and wash the tanks in a priority order is also included. Therefore, it is possible to provide a new technology that can achieve reasonable and efficient marine transportation of chemicals.

Constitution of the Invention According to the present invention, when there is a residual liquid in a hull, the residual liquid is removed, and the substance in which the residual liquid is volatilized (evaporated) is gasified, and the hull is cleaned after removing the gas. Related to

Although the cleaning treatment of the present invention can be applied to a chemical tanker having a single tank, as described in detail below,
A cleaning system including the above-mentioned hulls, of which at least one of the hulls is an advantageous cleaning condition under conditions of being subjected to the cleaning process.

That is, the present invention provides a method for selecting a hull to be subjected to a cleaning process from one or more hulls to be subjected to a cleaning process, exposing the remaining liquid in the hull in the selected hull to a line or a straw line. Through a pump to collect in a waste liquid tank, and then wash the tank with a water-soluble organic compound, wash with detergent-containing water, wash with fresh water, wash with seawater, and heat-treat with steam. Method (a) Detergent-containing water washing, seawater washing, freshwater washing and steam heat treatment, (b) seawater washing, freshwater washing and steam heating treatment, (c) freshwater washing and steam heating treatment, and (d) water-soluble organic compound One of the cleaning methods is selected. According to the selected method, a predetermined cleaning liquid or a plurality of cleaning liquids and steam (hereinafter, also referred to as a cleaning fluid). Guiding a predetermined washing fluid from a supply source to the washing means in the hull to wash the hull, or sequentially guiding a plurality of washing fluids to the washing means in the hull in accordance with the method; This is a method for cleaning a hull of a chemical tanker having a plurality of hulls, wherein each rinsing is performed and the cleaning process is automatically performed by remote control.

 The present invention will be described.

The present invention is a method for automatically processing the cleaning of a hull,
The hull is cleaned by automation, unmanned operation, and remote control.

In chemical tankers with multiple tanks, the cargo (chemicals) loaded in each tank varies widely, and when loading foreign cargo after unloading, the previous cargo remains in the tank. You need to clean it completely so you don't. However, it is no exaggeration to say that the most troublesome operations for the chemical tanker are the residual liquid treatment of the preload and the cleaning of the hull, as described.

The residual liquid treatment in the hull is based on the following steps. First, the remaining liquid in the hull is pumped up by a pump through a flush line or a straw line, and is collected in a waste liquid tank provided at a bow (or a stern or another part). Next, washing with fresh water is simply performed, and the collected liquid and the residual liquid are collected in the waste liquid tank. Conventionally, an operator who has taken over the recovery of the residual liquid and put on protective equipment has entered the tank and wiped off the residual liquid in the well and the like. In addition, floors, walls,
The remaining liquid adhering to the ceiling etc. is volatilized by a fan,
It must be forcibly discharged out of the tank. Since the residual liquid is almost harmful and toxic to the human body without exception, it is desired that the residual liquid be unmanned or automated from the viewpoint of work safety even though it is equipped with protective equipment. The residual liquid processing operation finally activates the gas detection to confirm that no toxic gas remains in the tank. For some chemicals, there is a sensor that detects the gas concentration when gasified, but there is generally no automatic detection means. If toxic gas remains in the hull, it is necessary to wipe off the remaining liquid again or to exhaust the gas thoroughly by using a forced fan.

After the residual liquid processing is completed, the cleaning processing is performed next.
Conventionally, the cleaning work has been performed manually, so that workers have been mobilized to perform cleaning of the hull. It is desirable from a safety standpoint that the unmanned cleaning work is freed from dangerous work such as cleaning the hull, and if the work can be standardized, it will be affected by the experience, judgment and skill of the workers. In addition, there is also an effect that an accurate processing state is guaranteed.

 The automatic cleaning of the hull constitutes the present invention.

In the present invention, each vessel is first equipped with a washing means such as a sprinkler. The number of the washing means, the spatial position, the direction in which the washing liquid is jetted during washing, and the jet strength are preferably adjusted so that the washing liquid reaches all of the ceiling, walls and floor of the hull. Generally, efficient cleaning means include a cleaning liquid ejector that changes its direction by a reaction of the ejection (with a rotatable ejector) and / or a shaft on which the ejector rotates with the ejection. Is mechanically rotated in another axial direction, and with such a function, ceilings and walls can be thoroughly washed with a small number of washing means. It is necessary to provide at least one, preferably two or more washing means in the hull. The washing means may be installed on a ceiling or a wall to fix the spatial position, slide on a support, or hang from the ceiling (movable up and down). , And the size can be determined as appropriate.

A storage tank for the cleaning liquid may be provided outside the vessel to serve as a supply source of the cleaning liquid. Fresh water can be supplied directly from a water tank installed in a ship as a supply source of cleaning liquid, and seawater can be directly supplied as a supply source by pumping with a pump. Of course, a liquid storage tank may be provided for each type of cleaning liquid. Examples of the washing liquid include water-soluble organic compounds such as methanol and acetone, detergent-containing water, fresh water, and seawater. The supply source of the cleaning liquid and the plurality of cleaning means are connected by a pipe. The supply source and the pipe are provided with an opening / closing valve, a switching cock, and the like, so that the selected cleaning liquid is sent to a predetermined cleaning means. ing. If a liquid feed pump is arranged in the middle of the pipe or a pressurizing means for pressurizing the cleaning liquid of the supply source is provided, the cleaning operation proceeds smoothly.

According to the present invention, first, there are a step of selecting a hull to be subjected to a cleaning process, a step of selecting a cleaning method for cleaning the hull, and a step of subsequently cleaning the hull. Once the tank to be cleaned is determined, an on-off valve provided in the middle of the pipe so that the cleaning liquid is not sent to other tanks so as to be supplied to the cleaning means provided in the tank. Are opened and closed, and a cock or the like for determining a flow path is installed at an appropriate position. If the on-off valve and the switching cock of the flow path are provided as electromagnetic valves, the opening and closing of these can be accurately and remotely controlled. When changing the hull or setting the next hull after the cleaning processing of one hull, the solenoid valve at a predetermined position may be opened and closed by the same procedure. For example, 4
In the case of a tanker having about eight tanks, the tanks may be assigned the first to fourth to eighth orders, and a selection control method may be adopted so that one of the tanks can be selected.

In the next cleaning method, the amount of the cleaning liquid used and / or the cleaning processing time may be set in advance, and the order of the cleaning liquid and the timing of supplying steam may be program-controlled. In this case as well, the opening and closing of the supply source of the cleaning liquid and the opening and closing of the supply source of water vapor may be set as easy means for controlling a solenoid valve or the like, and sequence control may be performed. The most complicated cleaning process is to spray detergent in the hull and supply fresh water, or to wash by spraying detergent-containing water, further wash with seawater under predetermined conditions, and finally wash with water, And a heating step of performing washing under heating (drying by heating) under heating and controlling the heating so as to meet a predetermined schedule. If the washing process is completed only by washing with water or by washing with water and steam, a simple program is sufficient.

 The operation of the present invention will be supplemented with reference to the drawings.

FIG. 1 is a perspective view showing an outline of a cleaning facility for applying the cleaning method of the present invention. A chemical tanker equipped with four oil tanks (ship tanks) and a waste liquid tank is equipped with a complicated pipeline that enables landing of oil, washing of tanks, and loading of oil ( The drawings are partially omitted).

For example, after the cargo oil in the No. 1 cargo oil tank is unloaded by the cargo handling pump, the residual liquid is pumped off (installed on the deck in the figure).
And is collected in a waste liquid tank via a flush line. In the cleaning process of the hull, clean water containing or not containing detergent is supplied to a cleaning machine (cleaning means) suspended from the ceiling, a simple preliminary cleaning is performed, and the cleaning liquid is reapplied to a waste liquid tank via a line. send. Air is blown into the hull or a fan (not shown) is rotated to remove gas until odor does not remain in the hull.

Next, the bottom valve for seawater intake is opened to introduce seawater, and the tank is washed with seawater. After seawater washing, freshwater is pumped from the freshwater tank by the washing pump and supplied to the cleaning machine. After the fresh water washing process, steam is guided from the steam inlet, and the inside of the hull is heated and dried by steam steaming. After steam steaming, natural drying or high-speed drying treatment with dry air is performed. In this way, washing and drying of the No. 1 oil tank are completed.

In the case where fresh water and detergent washing are performed, the steam steaming and subsequent steps are omitted, fresh water is poured into this oil tank, and a necessary amount of detergent is supplied to serve as a supply source of detergent-containing water. It can be used for cleaning the ship tank.

In the early stage of cleaning, the cleaning liquid after cleaning often needs to be collected in a waste liquid tank, but can often be discharged outboard at a later stage of the cleaning process. When discharging to the outside of the ship, open the outboard discharge valve to discharge.

FIG. 2 is a flowchart showing an operation of sending a cleaning liquid in the cleaning processing. The tank B is provided with cleaning machines 53 and 54 for washing. The bottom valve 24 is now opened to take in the seawater 14, and the pump 41 is operated to guide the seawater to the cleaning machines 53 and 54. At this time, fresh water supply means 11, detergent-containing cleaning liquid 12, water-soluble organic compound 13, vapor source 1
Automatic valves 21-23 and 2 to prevent 5 etc. from being sent to the washing line
5 is closed. In addition, the flow path switching valve and the on-off valve connected to the supply lines other than the tank B are all closed.

In the second stage of the washing program, the supply of seawater is stopped and the bottom valve 24 is closed, and the automatic valve 21 is opened instead. In the heating and drying by steam, the automatic valve 25 is opened, and steam is blown out from the steam outlet 62 of the hull B. Automatic valve so that supply to each tank can be stopped for the steam line
71 to 76 may be provided.

After performing the cleaning process of the present invention and, if necessary, the steam heating process, the ship tub is checked, and a process such as drying is performed, or if the cleaning is insufficient, further cleaning is continued. . When the cleaning is completed, it is possible to proceed to the next tank cleaning processing if necessary.

Next, the discharge of the used cleaning solution accompanying the cleaning process will be described. Used washing liquid (discharged liquid) is collected in a waste liquid tank, and can be discharged outboard (in the sea). For example, when washed with a water-soluble organic compound such as methanol, it is collected in a waste liquid tank, but in the case of finish washing with seawater or fresh water, it can be discharged into the sea. FIG. 2 is a flow chart for explaining the discharge processing, and the tanks A to D
Are provided with discharge valves 81 to 84, and the discharged liquid is collected by an outboard discharge 89 or a waste liquid tank Z by a pump 91. Whether the discharged liquid is discharged outboard or collected in a waste liquid tank can be selected by a switching valve 92. When a sensor 90 capable of analyzing the components of the discharged liquid is provided, the processing of the discharged liquid is automatically determined according to a standard, and the switching valve 92 can be automatically operated.

As described above, the present invention can be applied to the standard cleaning treatment of a chemical tanker. The cleaning system of the present invention
The hull is selected and the hull is cleaned. However, as the number of large tankers and hulls increases, two or more hulls can be cleaned at the same time.

INDUSTRIAL APPLICABILITY The present invention can perform a cleaning process on a hull during a voyage, and can perform a cleaning process in parallel with a boat maneuvering operation. According to the present invention, a cleaning operation panel is provided in parallel with the steering equipment, and a switch or the like provided on this panel can be operated to remotely control the cleaning of the hull. The washing operation panel is, for example, a graphic panel. When a button switch is pressed, an electromagnetic valve is operated, and an automatic valve or a switching valve for washing the hull is operated in a predetermined manner via a medium such as hydraulic pressure or pneumatic pressure. You. The treatment of the drainage drain is similarly operated. If the method of cleaning the hull is determined, the cleaning work can be performed according to a predetermined time schedule.If the timer automatic valve operation is linked, the entire work is automatically performed only by pressing the button switch on the panel board once at first. Can proceed. For example, the detergent-containing water cleaning is set for 20 minutes, seawater cleaning for 30 minutes, fresh water cleaning for 30 minutes, and steam pressurization for 1 hour.
Also, if the drain for washing with detergent is collected in the waste tank and the drain for the first 10 minutes of washing in seawater is collected in the waste tank, and the subsequent discharged liquid is set to be discharged outboard, the hull cleaning process will be performed according to this program. Will be applied.

By selecting the cleaning method described above and deciding the tank to be cleaned, it is possible to carry out the operation by complete automation and unmanned operation.

 Hereinafter, the present invention will be further described with reference to examples.

Example 1 An example of cleaning a chemical tanker having first to fourth hulls by the method of the present invention will be described.

First of all, the tanks are simultaneously (or sequentially) operated, and the remaining lines are pumped up by operating the lines. Transfer the residual liquid to the waste tank in front. Next, each tank is washed with fresh water, and the water after washing at this time is also collected in the waste liquid tank. Forcibly operate the fan and discharge the vaporized (residual liquid) in the hull outboard. After the elapse of the predetermined gas free time, confirm that there is no gas in the tank by the gas detector.

After the preparation process, the fourth tank is cleaned with fresh water. The fourth tank is selected by the operation panel, and two cleaning machines in the fourth tank are suspended from the water tank. The valve of the predetermined pipe flow path was opened so that water could pass through the surface that rotates while jetting the surface, and the other valves were closed. The water after washing was discharged outside the ship because the water concentration was lower than a predetermined reference concentration. After washing for about 10 minutes, it was confirmed by a gas detector that there was no residual gas, and the washing was continued for about 30 minutes.

Next, about 30 m ³ of fresh water was introduced into the fourth tank, and a predetermined amount (0.1 m ³ ) of a detergent was charged, and the fourth tank was used as a supply source (liquid storage tank) of detergent-containing water. As in the fourth tank, the second tank, in which the residual liquid treatment was completed and gas free was completed, was washed with detergent-containing water.

The second hull operates the cargo pump to pump up the cleaning liquid from the fourth hull and sends it to the cleaning machine installed in the second hull. Washing treatment was performed using detergent-containing water for about 10 minutes. This washing liquid was collected in a waste liquid tank.

Subsequently, seawater washing was performed for about 10 minutes. Seawater is taken in by opening the bottom valve and leading to the second tank. After the seawater washing treatment, it was further washed with fresh water for about 10 minutes. This washing with fresh water was the same as the case where the fourth tank was washed.

The three-step cleaning with the cleaning liquid is performed in such a manner that when the detergent cleaning method is selected on the operation panel provided near the panel panel that performs the ship maneuvering operation, the cleaning process for about 10 minutes is automatically performed as a standard cleaning sequence. The automatic opening / closing of the automatic valve, the operation of the pump for supplying the predetermined cleaning liquid, and the stop are programmed.

After the cleaning process, steam was introduced from the steam inlet, and steam was ejected from the steam outlet (a cleaning machine could be used) of the second hull. When the heated steam was blown for about 1 hour, the inside of the hull reached about 60 ° C.
° C).

Since the packings (manhole packings) had the most residue on the inside of the hull, the state of the cleaning treatment was checked until the odor of these members was eliminated.

In the process of discharging steam from the hull to the outside with a fan or the like, drying has been performed, though insufficiently.

In addition to drying naturally over time, the drying time can be shortened by circulating the air in the hull through a desiccant such as lithium chloride.

The first hull could be subjected to the cleaning treatment and the heat treatment with steam similarly to the second hull, using the detergent-containing water remaining in the fourth hull.

Example 2 According to Example 1, a method of performing fresh water washing and steam steaming was applied. In FIG. 2, the open / close valve 21 is opened from the fresh water supply source 11, and the cleaning machine 55 of the third tank C and
Activated 56 and washed for 10 minutes, and this washing solution (after use) was discharged into seawater. Next, steam was introduced from the steam inlet 15 and the inside of the hull was dried for about 1 hour.
The hull was virtually dry with no residual gas.

According to the present invention, a predetermined cleaning program can automatically perform a cleaning operation on a predetermined hull by selecting one of various cleaning processing methods. It can be standardized and can be uniformly washed, and is efficient.

Further, since the washing operation can be performed during the voyage, there is an advantage that the transportation efficiency is improved. In addition, since it can be remotely operated while maneuvering, there is a safety and labor saving effect.

[Brief description of the drawings]

FIG. 1 is a perspective view (perspective view) showing an embodiment of the present invention. FIG. 2 is a schematic view of a pipeline according to an embodiment of the present invention. In the figure, A, B, C and D are ship tanks, Z is a waste liquid tank, 11
Is a fresh water storage tank, 14 is a seawater intake, 41 is a pump, and 51 to 58 are cleaning machines.

Continuation of front page (56) References JP-A-60-15290 (JP, A) JP-A-50-149088 (JP, A) JP-A-57-110577 (JP, A) JP-A-60-229897 (JP, A) , A) Japanese Utility Model Showa 57-135000 (JP, U) Japanese Utility Model Showa 47-38748 (JP, Y1)

Claims (2)

(57) [Claims] 1. A tank to be cleaned is selected from one or a plurality of tanks to be cleaned, and the remaining liquid in the selected tank is exposed through a line or a straw line. Pumping and collecting in a waste liquid tank by a pump, and then washing the tank with a water-soluble organic compound, washing with detergent-containing water, washing with fresh water, washing with seawater, and heating with steam. Method (a) Detergent-containing water washing, seawater washing, freshwater washing and steam heating treatment, (b) seawater washing, freshwater washing and steam heating treatment, (c) freshwater washing and steam heating treatment, and (d) water-soluble organic compound One of the two types of cleaning liquid, and a predetermined cleaning liquid or a plurality of cleaning liquids and water vapor are supplied from a predetermined cleaning liquid supply source in accordance with the selected method. Introducing to the selected washing means in the hull to wash the hull, or by sequentially introducing a plurality of cleaning liquids / water vapors to the washing means in the hull in accordance with the method, washing and heating each of the hulls. And a cleaning method for a chemical tanker having a plurality of tanks, the method comprising automatically performing the cleaning process by remote control. 2. The method for cleaning a hull of a chemical tanker according to claim 1, wherein it is possible to select whether the used cleaning liquid waste liquid is collected in a waste liquid tank or drained outboard.