ES2232268B1 - EMERGENCY EMPTYING SYSTEM FOR LNG TRANSPORTATION TANKS. - Google Patents

Abstract

Emergency emptying system for LNG transport tanks. The invention comprises two pipes fixed to the internal lateral generatrix of the cistern, whose upper ends are essentially at the height of the longitudinal axis of the cistern, and whose lower ends reach the lower generatrix in which they are provided with closing means with valve. Said means are closed in normal operation, and in their case of tipping allow the emptying of the tank.

Description

Emergency emptying system for LNG transport tanks.

The present invention aims at a emergency emptying system for transport tanks of LNG.

In transport by tanks with trucks usual trailer of LNG liquefied natural gas, it is difficult and many times dangerous the fact of emptying the LNG from the cistern in accident case As is conventional, these tanks have a plurality of transverse baffle plates in cap spherical that divide the cistern into a series of compartments, and they are provided inferiorly with the mouth of emptying and filling of LNG in the stations for that purpose, both operations being carried out of emptying and filling the tank through the mentioned mouth. Yes the trailer truck suffers an accident, the emptying of the LNG from the cistern can be complicated and sometimes very dangerous depending on the position in which the tank is turned over after the accident.

Of course, for the emptying of LNG is not what same that the filling / emptying mouth is in a position or in another, since if said mouth in the overturned cistern is found in the volume occupied by the LNG in liquid phase, the emptying does not has special complications, but if the phase is found Soda emptying is more difficult.

The preceding exhibition highlights the drawbacks of LNG transport tanks conventional in case of accident and overturning of the tank with a difficult position of the corresponding drain / fill mouth in relation to the gas / liquid phases of LNG.

The aforementioned drawbacks have been totally eliminated through the emergency emptying system for LNG transport tanks object of the present invention.

The invention provides an arrangement of two pipes located in the internal lateral generatrix and lowering to the lower generatrix, presenting at its ends lower respective closing and valve means.

In accordance with the above, the system of emergency emptying for LNG transport tanks object of the present invention, it is essentially characterized because it comprises the arrangement of at least two open pipes at both ends that are fixed on the lateral generatrix internal of the cistern, whose upper ends meet essentially at the height of the longitudinal axis of the cistern, and whose lower ends reach the lower generatrix in those provided with valve closure means, the which are closed in normal operation, and where appropriate dump allow the emptying of the tank.

According to the invention, in cistern position dump one of the pipes is in gas phase and the other in phase liquid, whereby a pipe allows the increase and / or reduction of the gas phase pressure at convenience, and the other pipe allows the almost total emptying of the liquid phase.

The free ends of the pipes are slightly curved laterally.

These and other features will come off better than the detailed description that follows, to facilitate which It is accompanied by a sheet of drawings in which it has been represented a case study that is cited only by way of non-limiting example of the scope of the present invention.

In these drawings:

Figure 1 is a side elevation view of the cistern provided with the system of the invention coupled to the corresponding trailer truck.

Figure 2 is a cross-sectional view. cistern schematic showing the joined pipes internally to the lateral generatrix of the cistern wall in normal position

Figure 3 is a cross-sectional view. schematic of the tank in overturned position.

Figure 4 is a fragmented view of the end top free of side pipes shown in elevation side.

In accordance with the drawings, the system of emergency emptying for LNG transport tanks object of the present invention, is incorporated into the tanks of this type identified with the reference (C) coupled in the corresponding trailer truck (CT), whose tanks are provided below the corresponding conventional mouth (1) filling / emptying at loading / unloading stations in question.

The system of the invention comprises the arrangement of two pipes (2), (3) open at both ends, which are fixed inside and laterally in the generatrix internal side of the cistern wall (C).

Side pipes (2), (3) at their ends free upper (2a), (3a) end laterally in a short lower curved section (2'a), (3'a), as illustrated in the detail of figure 4. Said side pipes (2), (3), for their lower ends (2b) are coupled by a wall (4) in relation to the cistern wall (C), and are provided with closing means and valve.

Said lower ends (2b), (3b) of the two side pipes (2), (3), protrude through the mouth (1) of conventional filling / emptying, and are provided with the means of timely closing and valve, comprising respective valves (5), (5 ') and closure plugs (6), (6').

As illustrated in Figures 2 and 1, the ends (2a), (3a) upper, free and open of the two side pipes (2), (3) are essentially the same height relative to the middle main longitudinal geometric plane of the tank (C), and below the usual level (N) of the LNG surface with normal full tank, corresponding to the liquid and gaseous phases of LNG.

If interested, the invention provides that in each side there are several side pipes (2), (3) and have the same or different length and / or height, in order to ensure the emptying the tank (C) in case of an accident and that the tank stay in a strange position.

Figure 3 shows the cistern position dump, in this case, the pipe (2) is with its free end (2a) is in the gas phase above level (N), in whose case can be relieved or put pressure as appropriate, and with the  pipe (3) and through its free end (3a) you can proceed to the total empty case of the tank (C).

The invention, within its essentiality, can be put into practice in other embodiments that differ only in detail from that indicated solely by way of example, which will also achieve the protection that collect. It will be possible, then, to carry out this System of emptying of emergency for LNG transport tanks, with the means, most suitable components and accessories, being able to elements components be replaced by other technically equivalent ones, to be all included within the claims.

Claims (3)

1. Emergency emptying system for LNG transport tanks, which are provided with a plurality of transverse baffle plates in a spherical cap, and the corresponding lower mouth for filling and emptying LNG in the corresponding stations, characterized in that it comprises the arrangement of at least two pipes open at both ends that are fixed in the internal lateral generatrix of the cistern, whose upper ends are essentially at the height of the longitudinal axis of the cistern, and whose lower ends reach the lower generatrix in the which are provided with closing means with valve, which are closed in normal operation, and in their case of tipping allow the emptying of the tank. 2. Emergency drainage system, according to claim 1, characterized in that in the position of a tank flushed one of the pipes is in the gas phase and the other in the liquid phase, whereby a pipe allows the increase and / or reduction of the pressure in gas phase at convenience and the other pipe allows the almost total emptying of the liquid phase. 3. Emergency emptying system according to the preceding claims, characterized in that the free ends of the two lateral pipes are slightly laterally curved.