JPS6149193B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a floating roof with a non-flammable atmosphere, for example for an underground tank for petroleum storage.

In the conventional floating roof of an underground petroleum storage tank, many pontoons formed inside the tank are open, and there is a strong possibility that a flammable atmosphere will exist inside each pontoon. Therefore, it is conceivable to seal each pontoon and form an inert gas supply port and a discharge port in each pontoon, but this would require a large number of supply ports and discharge ports, which would be uneconomical. Therefore, it is conceivable to communicate the sealed pontoons with each other through piping, but this configuration requires fewer inert gas supply ports and exhaust ports, but on the other hand, it requires a large number of piping. , it is uneconomical. Also, if one of the pontoons is damaged, inert gas will leak and a non-flammable atmosphere cannot be maintained.

Therefore, the present invention provides a floating roof with a nonflammable atmosphere for a tank that solves these problems. The airtight floating roof body formed by an annular outer rim plate is divided into a plurality of blocks that are isolated from each other, and inner rim plates and bulkheads are arranged in a lattice pattern at appropriate locations within each block. The pontoons formed by the inner rim plate and the bulkhead are made to communicate with each other by cutting out the block, and an inert gas supply port and a discharge port are formed in each block. Since the number of supply ports and discharge ports is small, and the pontoons communicate with each other through cutouts in the inner rim plate and bulkhead, piping connecting the pontoons is not required. Therefore, it is highly economical. Furthermore, even if one pontoon is damaged, the block other than the one to which the damaged pontoon belongs remains sealed, so the floating roof as a whole can maintain a non-flammable atmosphere and there is no risk of a fire.

Hereinafter, one embodiment of the present invention will be described based on the drawings. This embodiment relates to a floating roof structure for an underground tank for petroleum storage, and 1 is a floating roof body disposed in a tank body 2 so as to be able to rise and fall freely, and includes upper and lower deck plates 32 and 33, and both deck plates 32 and 32. ,3
Outer rim plate 3 arranged between the outer peripheral edges of 3
It is composed of 4. A seal 7 is disposed on the outer circumferential surface of the floating roof body 1 and abuts on the inner circumferential surface of the tank body 2, and a seal 10 is disposed upright on the bottom surface of the tank body 2 and whose upper end penetrates the floating roof body 1. Pipe shaft 11 is disposed within the shaft 10 and has a lower end opening protruding into the tank body 2 and an upper end opening protruding upward from the top of the pipe shaft 10; 12 is a drain pump piping disposed within the pipe shaft 10; Drain pump piping 1 at the bottom of
1 is a pump interposed therein; 13 is a shaft support whose base end is fixed to the upper end of the outer circumferential wall of the tank body 2 and whose tip through hole fits into the upper end of the shaft 10; 19 is a shaft support of the floating roof body 1; This is a foldable drain pipe that communicates the rainwater outlet and the lower end opening of the discharge pump pipe 11. The floating roof main body 1
The inside of the block is divided into a plurality of blocks (10 blocks in this embodiment) by a partition wall 35, and inside each block is a plurality of inner rim plates 36 and a bulk head 37, and a large number of pontoons 38. It is divided into Reference numeral 39 denotes notches formed at appropriate locations in each inner rim plate 36 and bulk head 37, which allow adjacent pontoons 38 to communicate with each other and form a zigzag-shaped passage within each block. There is. Reference numerals 40 and 41 are inert gas (for example, _N2 gas) supply and discharge ports formed in each block. It has an on/off valve. 42 is an inert gas supply tank arranged on the ground, 43 is a supply port of the inert gas supply tank 42 and each block.
This is piping that connects to the supply port 40 of the feeder.

In the above configuration, the inert gas supply tank 42
The supply port of each block is communicated with the supply port 40 of each block via piping 43, and inert gas is supplied into each block.
The air inside the tube is discharged from the discharge port 41. Once each block is filled with inert gas, the on-off valves of the supply port 40 and the discharge port 41 are closed to seal each block, and the pipe 43 is removed.
As a result, the floating roof main body 1 becomes a non-flammable atmosphere. Alternatively, the supply port of the inert gas supply tank 42 and the supply port 40 of each block can be connected by a flexible pipe so that inert gas can be constantly supplied to each block.

As described above, according to the floating roof of the tank of the present invention having a non-flammable atmosphere, the number of inert gas supply ports and discharge ports can be reduced, and each pontoon has a notch in the inner rim plate and bulkhead. Since the pontoons are communicated with each other through the pontoons, there is no need for piping to connect each pontoon. Therefore, it is highly economical. Furthermore, even if one pontoon is damaged, the block other than the one to which the damaged pontoon belongs remains sealed, so the floating roof as a whole can maintain a non-flammable atmosphere and there is no risk of a fire.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, in which FIG. 1 is a schematic vertical sectional view, FIG. 2 is a plan view of a floating roof, and FIG. 3 is a cutaway perspective view of the main part. 1... Floating roof body, 2... Tank body, 32,
33... Deck plate, 34... Outer rim plate, 35... Partition wall, 36... Inner rim plate, 37... Bulkhead, 38... Pontoon, 39... Notch, 40... Supply port, 41...
Discharge port, 42...Inert gas supply tank.

Claims (1)

[Claims] 1. The inside of the sealed floating roof body formed by the upper and lower deck plates and the annular outer rim plate arranged between the outer peripheries of both deck plates is divided into a plurality of blocks that are isolated from each other, and each The inner rim plate and bulk head, which are arranged in a lattice pattern inside the block, are cut out at appropriate places to communicate each pontoon formed by the inner rim plate and bulk head, and each block is provided with an inert gas supply port and a discharge port. A floating roof with a non-flammable atmosphere for a tank characterized by forming a .