DELIVERY OF FIRE-EXTINGUISHING MATERIAL BY A PRESSURE GAS SOURCE

Abstract: The invention relates to a fire-fighting equipment, comprising a hydraulic accumulator (H) and a pressure gas source (T) connected thereto for driving liquid by means of pressure gas out of the hydraulic accumulator through an outgoing liquid tube (6) arranged in the accumulator. The object of the invention is to provide a novel equipment permitting an efficient liquid delivery from one hydraulic accumulator (H) or a plurality of hydraulic accumulators (H, H'), by mixing gas efficiently in the liquid immediately from the beginning. This is achieved in such a way that the outgoing liquid tube (6) comprises a throttling (11) and that to the liquid tube (6), after said throttling (11), is connected a throttled gas inlet (13) preferably from the same pressure gas source that is connected to the hydraulic accumulator (H) for driving liquid out of this accumulator.

Description: DELIVERYOFFIRE-EXTINGUISHING MATERIALBYA PRESSUREG A S SOURCE The present invention relates to a fire-fight¬ ing equipment, comprising a hydraulic accumulator and a pressure gas source connected thereto for driving liquid by means of pressure gas out of the hydraulic accumulator through an outgoing liquid tube arranged in the accumulator. Certain kinds of petrol fires, e.g. a kerosene fire in a jet engine of an aeroplane during engine test in a hangar intended for that purpose, are almost impos¬ sible to extinguish, even by means of strong fog-like liquid sprays, as is proposed e.g. in the International Patent Application PCT/FI92/00155. Such a jet engine fire is not extinguished until the whole hangar in ques¬ tion, which may typically have a volume of about 3000 cubic metres, has been subjected to so-called "total flooding", which means that it has been filled with a liquid fog consisting of very small drops practically entirely. The liquid fog required can be generated in principle by means of an equipment described in the In¬ ternational Patent Application PCT/FI92/00317. In said application, an outgoing rising pipe of a hydraulic ac- cumulator is provided with apertures in its wall so that the drive gas of the accumulator initially drives out liquid only and the drive gas is being mixed into the outgoing liquid gradually after the liquid level has fallen to the level of the uppermost aperture in the tube wall, in increasing proportions according to the falling liquid level and more apertures in the tube wall becoming free. During final discharge stage of the accu¬ mulator, a liquid fog consisting of drops small enough for the present purpose can be achieved, but a far too large part of the liquid of the hydraulic accumulator is lost. The gas source may be a container including nitrogen gas and having a charge pressure of e.g. about 200 bar, and it can be arranged to feed one hydraulic accumulator or a plurality of hydraulic accumulators connected in parallel. The object of the invention is to provide a novel equipment enabling an efficient liquid delivery from one hydraulic accumulator or a plurality of hydrau¬ lic accumulators by mixing gas efficiently in the liquid immediately from the beginning. The equipment according to the invention is mainly characterized in that the outgoing liquid tube comprises a throttling and that to the liquid tube, after said throttling, is connected a throttled gas inlet from a pressure gas source having a pressure higher than the liquid pressure after the throttling of the outgoing liquid tube. In a preferred embodiment of the invention, the pressure gas source connected to the throttled gas inlet is the same that is connected to the hydraulic accumu¬ lator for driving liquid out of this accumulator. The throttling of the outgoing liquid tube and the throttled gas inlet are hereby preferably adapted to provide at least essentially equal pressure drops. If the gas source has a pressure of 100 bar, the respec¬ tive throttlings can be dimensioned to provide a pres¬ sure drop of e.g. 5 bar. If the pressure gas source is constituted by a pressure bottle, this can be connected to the hydrau¬ lic accumulator through a check valve loaded against the gas pressure, which valve shuts off the gas supply at a predeterminable pressure. Subsequently, the gas enclosed in the accumulator continues driving out gas by expanding, while the gas source continues delivering gas only through the throttled inlet after the throt¬ tling of the liquid tube. In a preferred embodiment, the pressure gas source is coupled to the hydraulic accumulator through a connection, which comprises a housing provided with a gas inlet to the accumulator, an outgoing liquid tube and a mounting part for mounting in the outlet of the hydraulic accumulator, whereby the throttling of the outgoing liquid tube extends through the mounting part of the housing and the throttled gas inlet after the throttling of the liquid tube is constituted by at least one aperture in the wall of the liquid tube, which aper¬ ture is in contact with the gas inlet of the connection into the hydraulic accumulator. A ring channel between the throttling of the liquid tube and the mounting part surrounding the throttling offer a simple solution to an efficient gas supply at a high pressure. If the gas source feeds more than one hydraulic accumulator, a gas outlet to the gas inlet of an adjac¬ ent accumulator connection may preferably be arranged within the extent of the throttling of the liquid tube. In the following, the invention will be de¬ scribed with reference to the attached drawing including Figures 1, 2 and 3, showing two preferred embodiments of the equipment according to the invention. The embodiment shown in the Figures 1 and 2 contains a connection A, comprising a housing 1 provided with a gas inlet 2 for being connected to a pressure gas source T, a threaded outgoing liquid tube 3, a hold 4 for a safety plug or alternatively a gas outlet 4 (pre¬ ferably of the same form as the inlet 2) to an adjacent similar connection A' of an adjacent hydraulic accumula¬ tor H' and a mounting part 5 provided with an external thread to be mounted in the outlet of a hydraulic accu- mulator H. An outgoing rising tube of the hydraulic accumulator H is indicated by 6. An outlet end 7 of the tube 6 is connected to the outgoing tube 3 by means of a shear ring coupling 8. A support ring is indicated by 9 and a sealing ring arranged in connection with this is indicated by 10. The tube 6 portion extending inside the mount¬ ing part 5 of the housing 1 in front and preferably in¬ cluding the gas inlet 2 as well is throttled in relation to the rest of the diameter dimension of the tube 6 and indicated by 11. Thanks to the throttled tube portion 11, a pressure drop is provided, as well as a ring chan¬ nel 12 between the tube portion 11 and the housing 1 from the gas inlet 2 along the mounting part 5 of the housing into a liquid container of the hydraulic accumu¬ lator H. The ring channel 12 permits an efficient supply of drive gas to the liquid container of the hydraulic accumulator H and through that an efficient delivery of liquid into the outgoing tube 3. After the throttling 11 is arranged a throttled gas inlet 13, which may be a suitably dimensioned aper¬ ture in the wall of the tube 6 and in direct contact with the gas inlet 2, as suggested in the drawing. The pressure drop of the outflowing liquid over the throttling 11 is preferably equal to the gas pres¬ sure drop in the throttled inlet 13, e.g. about 5 bar. A spring-loaded F check valve B acting against the pressure of the gas flowing through the ring channel 12 can be positioned around the liquid tube 6 before the throttling 11, e.g. in such a way that a ring element R strives to bear against the end of the mounting part 5. The throttling of the tube portion 11 can be performed conveniently e.g. by means of existing clamp- ing means for hoses of different kinds. As to the other parts, the connection according to the invention is an extremely simple construction. Figure 3 shows an alternative embodiment. The liquid container of the hydraulic accumula¬ tor is not shown in the drawing. As to the liquid con¬ tainer and other general arrangements, reference is again made to Patent Applications PCT/FI93/00429 and FI 931405, Figures 7 to 9.

Claims: AMENDED CLAIMS [received by the International Bureau on 10 August 1995 (10.08.95); original claims 1-8 replaced by amended claims 1-9 (2 pages)] 1. A fire-fighting equipment, comprising a hydraulic accumulator (H, H") with a liquid container and a pressure gas source (T, T"), a connection (A, A") being provided for connecting the pressure gas source (T, T") to the hydraulic accumulator (H, H"), said pres¬ sure gas source being adapted to drive liquid by means of pressure gas out of the hydraulic accumulator (H, H") through an outgoing liquid tube (6, 6") arranged in the accumulator, a throttling (11) being provided in the liquid tube (6, 6") the connection comprising a housing (1, 1") with a gas inlet (2, 2") to the accumulator (H, H") and a mounting part (5) to be mounted in the outlet of the hydraulic accumulator, c h a r a c t e r i z e d in that the throttling (11) of the outgoing liquid tube (6, 6") comprises a throttled tube portion (11) made in one part with the outgoing liquid tube (6, 6") by cla p- ing said tube, said throttling (11) extending through the mounting part (5) of the housing (1, 1") whereby a ring channel (12), known per se, is provided between the tube portion (11) and the housing (1, 1"), said ring channel extending from the gas inlet (2, 2") along the mounting part (5) of the housing into the liquid con¬ tainer of the hydraulic accumulator (H) . 2. An equipment according to claim 1, c h a r¬ a c t e r i z e d in that the throttling (11) of the liquid tube (6, 6") extends somewhat past the mounting part (5) into the liquid container of the hydraulic accumulator (H, H") . 3. An equipment according to claim 1, c h a r¬ a c t e r i z e d in that to the liquid tube (6, 6" ) , after said throttling (11), is connected a throttled gas inlet (3, 3") from a pressure gas source having a pres- sure higher than the liquid pressure after the throt¬ tling (11) of the outgoing liquid tube (6, 6") . 4. An equipment according to claim 3, c h a r¬ a c t e r i z e d in that the pressure gas source (T, T") connected to the throttled gas inlet (13, 13") is the same that is connected to the hydraulic accumulator (H, H") for driving liquid out of this accumulator. 5. An equipment according to claim 3, c h a r¬ a c t e r i z e d in that the throttled gas inlet (13, 13") after the throttling (11) of the liquid tube is constituted by at least one aperture (13, 13") in the wall of the liquid tube (6, 6"), which aperture is in contact with the gas inlet (2) of the connection to the hydraulic accumulator (H, H") . 6. An equipment according to claim 1 or 2, c h a r a c t e r i z e d in that the pressure gas source (T) is connected to the hydraulic accumulator (H) through a check valve (B) loaded against the gas pres¬ sure and shutting off the gas supply at a predetermin- able pressure. 7. An equipment according to claim 6, c h a r¬ a c t e r i z e d in that the check valve (B) comprises a ring element (R) positioned around the liquid tube (6) and loaded by a spring (F) . 8. An equipment according to claim 1, c h a r¬ a c t e r i z e d in that a gas outlet (4) to the gas inlet (2') of an adjacent accumulator (H') connection (A 1 ) is arranged within the extent of the throttling (11) of the liquid tube (6) . 9. An equipment according to claim 1, c h a r¬ a c t e r i z e d in that the inlets (2", 2"') of two hydraulic accumulators (H", H" ' ) are connected in paral¬ lel to a common gas source (T") .

Inventors: SUNDHOLM GOERAN, SUNDHOLM, GOERAN
Applicants: SUNDHOLM GOERAN, SUNDHOLM, GOERAN
Application year: 1995
Main classification: A62C31
IPC codes: A62C3, A62C35, A62C39