JPS607111B2 - Plant construction and operation method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to methods for constructing and operating various plants such as chemical plants, desalination plants or power plants.

Traditionally, when constructing these plants, a large number of equipment and parts manufactured at a factory were shipped to the site and then assembled and installed in a large building, equipment was interconnected with piping, or Complex processes were required, including instrumentation and electrical work, as well as various tests and trial runs, and various preparations were required before plant operation.

However, with such conventional plant construction and operation methods, the working environment in a broader sense varies greatly depending on local circumstances, so the construction period and cost fluctuate significantly.
Problems include the need for a large space due to the site's location, the many unforeseen dangers associated with land transportation and on-site work, and the fact that a considerable amount of preparation time is required after the plant is constructed before it can begin operations. There is a problem.

Therefore, it may be possible to start operation of the plant after loading the plant onto a floating body, sailing it to a designated location, and emplacement; however, in such a case, the bottom section of the floating body containing piping for the plant would be made of steel. Therefore, it is necessary to apply sufficient coating to prevent corrosion. However, painting alone may cause mist to form on the inner walls of the compartments during navigation when there is a large temperature difference between day and night, and salty outside air may enter the compartments over time. There is a problem in that it corrodes the constituent steel materials.

In particular, when sailing through tropical regions, or where there is a large difference in temperature between day and night, condensation forms inside the multi-bottom, which cannot be properly maintained, and corrosion is likely to occur inside the multi-bottom due to the salty outside air. It is necessary to pay sufficient attention to its corrosion protection.

The multi-bottom of a floating body is an important structure that maintains the structure of the floating body during navigation and serves as the foundation structure for plant installation. Corrosion prevention, which is directly related to maintaining the structural strength of the floating body, is important for the plant. This is an important issue during transportation, construction, and operation.

The present invention aims to solve these problems.
The plant is mounted on a floating body, which is a buoyant structure like a ship's hull, and the buoyancy is used to transport the plant to a designated location, and the floating body is placed in place before starting operations. It is an object of the present invention to provide a method that enables the floating body to be constructed and operated, and to sufficiently prevent corrosion within the floating body by using an inert gas.
For this reason, the plant construction and operation method of the present invention involves constructing a plant structure consisting of a steel floating body with multiple bottoms and a plant mounted on this floating body, and then applying an internal pressure slightly higher than atmospheric pressure. Inert gas for anti-corrosion is filled in the required sections within the multi-bottom, and then the plant structure is floated on water and sailed along a waterway to a designated location where it is established.
It is characterized by starting the operation of the above plant.
According to the above-described plant construction and operation method of the present invention, even in the case of a plant including a reaction tower or a distillation tower, it is possible to assemble these together with floating bodies to a nearly completed state as a plant structure in a factory. In addition to significantly eliminating on-site construction work, transporting the buoyant plant structure by navigating it along a waterway to a designated location is extremely easy; Since the process is carried out under stable conditions, it can be started very safely and efficiently at an early stage.After construction, inert gas is applied to the compartments within the multi-bottomed structure of the plant structure, which is then applied with an internal pressure slightly higher than atmospheric pressure. Since the air inside the compartment is filled with an inert gas such as, the air in the compartment is replaced with the inert gas, and the internal pressure is maintained slightly higher than atmospheric pressure while the oxygen concentration is reduced.

As a result, the inner wall of the compartment as well as the piping necessary for the plant are sufficiently protected from corrosion.

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a plant structure according to the present invention, which includes a watertight side skin la, a double bottom lb, a multilayer deck structure lc, etc. A floating body 1 constructed like a ship's hull structure supports various types of equipment 2 such as reaction towers using each deck structure lc, and also has piping work, instrumentation work, electrical work, etc. carried out to support a chemical plant. The component equipment is mounted and constructed until it is almost completed, and in this way, the buoyant plant structure A is constructed. FIG. 2 is a partial detailed sectional view of a compartment in the bottom of the vehicle, showing that the inside of the double bottom lb is partitioned by a partition wall 4 and divided into several compartments 3.

There is a partition wall 5 within the same compartment 3, which allows people to pass through a closure 6, and each space 3a, 3b
are in the same section.

The portion 8 where the piping 7 in the double bottom penetrates the partition wall 4 is made fluid-tight due to the necessity for transportation as a floating body.

Also, each space 3a within the same section 3. 3b is a ventilation hole 9 and a drain hole 10 provided in the partition wall 5 between them.
1, the corners above or below Sekiguchi 6 are also spatially connected.

Each compartment 3 in the double bottom lb has at least one manhole 11 and a pent pipe turtle 2, and the pent pipe 12 is equipped with a breathing device 13 to control the increase and decrease of pressure inside the double bottom. It is adjustable.

The inside of each space 3a, 3b of the double-bottom inner compartment and the outside of the piping 7 are coated with an appropriate coating, and an inert gas is filled in to create an internal pressure slightly higher than atmospheric pressure inside this compartment. It is set so that it takes The plant structure A is constructed in a construction dock at a factory, and if necessary, its trial operation is carried out in the construction dock.

After construction, ``before transportation, an inert gas for anticorrosion such as inert gas is filled with an internal pressure slightly higher than atmospheric pressure.

Then, by injecting water into the construction dock, plant structure A
is floated on water and transported to a designated location by towing or self-propulsion along a waterway.

As shown in FIG. 3, an installation dock 20 is constructed in advance at a predetermined location 19, and the plant structure is passed from the waterway 18 through a dock gate (not shown) that can be closed off to the dock 20.
It is designed to be placed within 0. FIG. 4 shows the state in which the plant structure A has been towed along the waterway 18 and has arrived at the water area in the skirting dock 20 at the predetermined location 19.
In this state, the plant operating fluid 21 such as fresh water or liquid raw materials is introduced into the ballast compartment in the double bottom lb of the plant structure A, and the water in the dock 20 is pumped out, if necessary. An intervening material is interposed between the plant structure A and the plant structure A to be horizontally lowered and landed on the ground as shown in FIG.

As shown in FIG.
This prevents water from seeping through from other sources.

Note that when introducing the plant structure A into the installation dock 20, water can be poured into the dock 20 from the waterway 18 using high tide, and similarly, water can be drained from the dock 20 using low tide. can be done.

Furthermore, as shown in FIG. 6, the embankment 23 reinforced with concrete 22 is used as a breakwater or a barrier in case of plant damage even after the plant structure A is hemmed.

If the predetermined site 19 to which the plant structure A is to be attached is located on the coast, the ocean can of course be used as the waterway 18, and emplacement by anchoring is also possible. The plant structure A will be constructed along these waterways at the designated location 19 by using waterways or creating new excavations.
It can be sailed up to.

Note that if it is desired to move the plant structure A again after installation, it is also possible to float the plant structure A by filling water into the installation dock 20 and discharging ballast and the like.

As mentioned above, after the plant structure A is placed in place 19, the operation of this plant will begin.However, before the plant is transferred, the plant has already been built to a nearly completed state in the construction dock and, if necessary, a trial run is conducted. Since the plant structure has been completely completed, it is possible to start its operation with almost no preparatory equipment required. By being activated after A is placed in place, it is possible to operate extremely safely in a stable state without being affected by the oscillation of the floating body 1. Furthermore, in the method of this embodiment, as described above, inert gas is sealed in the compartment 3 in the double bottom at an internal pressure slightly higher than atmospheric pressure, so that air containing moisture and salt can be absorbed from the outside. prevent intrusion,
It also prevents moisture in the air from exceeding the saturation point of water vapor as the temperature decreases and turning into fog. In other words, air containing moisture causes electrochemical corrosion to the same aircraft as if steel were immersed in liquid. In addition, salt solutions have high conductivity, which accelerates corrosion due to battery action, but in this method, inert gas is sealed in the multi-bottomed chamber at an internal pressure slightly higher than atmospheric pressure, so moisture and This prevents salt-containing air from entering, thereby preventing corrosion.
Therefore, corrosion of the steel materials and piping as structural members inside the double bottom is sufficiently prevented, maintenance becomes easier, durability is increased, and the plant can be operated efficiently.

Note that the timing for filling inert gas into the required sections in the double bottom lb of plant structure A is the preparation time before starting navigation along the waterway; It goes without saying that if an inert gas is additionally sealed inside the bottom, it will be even more advantageous in terms of corrosion prevention.

Furthermore, if the space above the double bottom is filled with inert gas as the base of the multiple bottom, it will be extremely advantageous in terms of corrosion protection for plant equipment.

As detailed above, according to the plant construction and operation method of the present invention, various types of equipment hemming, assembly of parts, piping, electrical work, etc. can be carried out on a floating multi-layered deck structure at a factory construction dock, etc. The plant structure constructed in this way can be floated on water and transported to a designated site all at once, which eliminates the conventional method of transporting individual equipment to the site and assembling it. The various necessary works and construction work will be greatly simplified and management will be easier than in the case where it is carried out. In addition, because an inert gas for corrosion protection is sealed in the required compartments within the double bottom at a pressure slightly higher than atmospheric pressure, electrochemical corrosion caused by moisture-containing air is prevented.

Also, since it prevents air containing seawater salt from entering,
Acceleration of corrosion due to battery action caused by the conductivity of the salt solution can be prevented.

In this way, it is advantageous in various respects, such as improved durability, reduced costs, and operational safety.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a plant structure in the plant construction and operation method of the present invention, and FIG. 2 is a partially detailed view thereof.
3 to 6 are explanatory diagrams showing the installation process of the plant structure at a predetermined location. 1...Floating body, la...Side outer plate, lb...
...Double bottom, lc...Deck structure, 2...Various equipment, 3...Division within the double bottom, 3a, 3b.
... Space within the compartment, 4 ... Partition wall, 5 ...
・・Partition wall, 6・・・・gate, 7……piping, 8……
Part where the pipe penetrates the partition ~ 9...Vent hole, 10
..., drain hole, vine turtle... manhole, 12...
W pent pipe Military 3 states...Respiratory equipment Turtle 8...Waterway, Tomi 9 states...Specified location, 20...Installation dock ~ 2nd Army...Fluid for plant operation 22...Misaki concrete ij-ji-ji-ji-ji-ai 3...
...Dike, A...Plant structure. ★Figure 1 Figure 2 Figure 3 Tachizu Figure S Figure 6

Claims (1)

[Claims] 1 After constructing a plant structure consisting of a steel floating body with multiple bottoms and a plant mounted on this floating body,
Corrosion-preventing inert gas with an internal pressure slightly higher than atmospheric pressure is sealed in the required compartments within the multi-bottom, and the plant structure is then floated on water and sailed along a waterway to a designated location where it is placed. A method for constructing and operating a plant, the method comprising starting the operation of a plant.