US3282238A - Method and apparatus for discharging liquids from immersed vessels - Google Patents

Description

Nov. 1, 1966 A. J. TUCKER 3,282,238 METHOD AND APPARATUS FOR DISCHARGING LIQUIDS FROM IMMERSED VESSELS Filed July 20, 1965 A4570: f? e (X 72/04 er INVENTOR.

BY //4RR/s', (ARK/IV ANA WEQL 06K ATTORNEY o 3,Z%2,Z38 Umted States Patent ice 1,196,

there are no moving parts and because it will control 352329233 pressure differential with precision regardless of water METHQD AND AllPAlRATUS FOR DISCHARGING depth LEQUIDS g g f s -g EI Briefly stated, this invention is for a method of dis- Augusime John g i g 0st Oak 5 charging liquids from a liquid containing vessel immersed Filed 2%, 3 l 473,404 in an immersing medium, such as water, which comprises 14 Chm-mm (CL the steps of introducing a pressurized fluid, such as air, into the vessel at a pressure differential sufficient to dis- This invention relates to a method and system or applace the liquid therefrom. The liquid in the tank, such paratus for discharging liquids from an immersed vessel as water, is displaced therefrom by application of the or tank. More particularly, this invention relates to a pressurized fluid. When the pressure differential between method and apparatus or system for controlling the insidethe inside and outside of the vessel or tank exceeds a preoutside pressure differential in a tank or a vessel while determined level, (i.e., the safe internal stress capacity a liquid is being removed therefrom and while the vessel of the vessel) the inside pressure is relieved therefrom is immersed in an immersion medium such as a liquid. 15 by venting the pressurized fluid from a first point located This removal of the liquid may be, for example, the reinside the vessel and above the liquid level therein to moval of water from a submerged tank or vessel during a second point located exteriorly of the vessel and spaced a salvage operation wherein the water is displaced from below the first point a distance which is sufficient to the submerged tank or vessel to gain buoyancy. cause the venting to occur when the pressure differential In the process of raising tanks or vessels which are 0 exceeds the predetermined level. completely sunk or immersed, it is common practice for The system of this invention is adapted for dischargsalvors to install air connections to the tank spaces, ing a-liquid fromaliquid containing vessel immersed in an apply air pressure to blow the water out and gain buoyant im ng vmedium and includes means for introducing lift to bring the hull to the surface. The degree or amount a Pr s iz d fl i nt th ve s l to displace the liquid of air pressure required to accomplish this is proportional therefrom Outlet means are 3150 Provided for dischargto the water depth, with approximately one-half pound ing liquid from the vessel. In addition, there is provided f pressure b i i d to overcome h h d t i conduit means associated with the vessel for relieving the head pressure or outside pressure of each foot of water pressure inside the vessel when the pressure differential depth, inside and outside the vessel exceeds a predetermined Marine hulls are usually designed for an internal stress am n T s C n u m ans C mmu i at s b tw n a suflicient to withstand the hydrostatic head pressure of first point located inside the vessel and above the liquid the hull depth plus some margin of safety. When an level therein and to a second point located exteriorly of pressures are introduced into the tank when the tank is the vessel and spaced below the liquid level inside the submerged, the permissible amount of inside pressure vessel a distance Which is adapted to maintain the P must be controlled such that the inside-outside pressure determined Pressure differentialditferential does not exceed this designed bursting capacity, It i to he Understood th this inv nti n is particularly closely restricted to the safety factor. adaptable to raising or salvaging submerged or sunken Even though the hull is submerged to a considerable Vessels, as Will he @Xpiaifled hereinafter, but may 3150 depth, high air pressures can be applied to the inside of ha ility in unl ading liquid car-gos and ballast from the tank if the loading is no greater than the differential vessels and the likeof pressure between the outside hydrostatic head pressure Reference to the figures will further explain the inand the inside ressure. The t k ill b (lg-watered vention wherein like numerals refer to like parts and in through the valve in the bottom of the tank or vessel which! because the liquid or water contained in the tank will FI 1 i a s hem ic cro s-sectional view of a tank be reposed in the bottom and the air will be collecting showing the system of this invention installed therein. on the top, such that the pressure of the water plus th FIG. 2 is a schematic cross-sectional view of a ship hull pressure of the air is greater than the outside pressure Vessel having a dual system for y g out the liquid of the water alone. When all of the water has been discharging as taught y this inmillionpurged or displaced f om the t k, any excess i pres- FIGS. 3A, 3B, and 3C are schematic cross-sectiona sure will be relieved by Venting ut the b tt d h views showing a tank having the invention system installet system will be i b lan e therein, which tank is adaptable for rotation in the wate The precise control of the balance through the de- 0T Submefgihg medium, and Showing three difiel'em P watering cycle is very diflicult. If air pressure over the tiOIls during the rotationsafe pressure differential is applied while there is still a H 4 is another embodiment of th inventi n showir water level in the tank, the hull will burst because the a tank in schematic Cross-Sectional View, which tank water cannot be pressed ut f th b o valve fa t likewise adaptable for rotation or turning in the water i enough to open a relief passage for the pressure build-up. immersing medium- Therefore, cautious marine salvors have in some instances Referring now f ciosed h Vessel 11 installed spring loaded or weight loaded relief valves in Shown submerged in an immersing medium such as Wat O and is partially filled with a fluid, such as water, at

water level 12 therein.

Means are provided for dispersing the water from v sel 11 which means conveniently takes the form of we the top of the tank to blow off the excess air pressure. However, these valves are also under the hydrostatic head loading or outside water pressure, and are not wholly reliable within the small tolerances of pressure valve 13 which communicates with the exterior of t, allowed. Moreover, they often collect trash and rags, or vessel 11 and which is Operated by valve handle and hence may become stuck in the open position to from above Upon opening of valve 13 Water inside thereby vent all of the air pressure from the tank with set 11 may be displaced therethmugh .2 the exteriol resultant disaster if the tank has been partially raised. the vessel 11 upon application of fluid pressure to V6 It is, therefore, an objective of this invention to pro 11 vide an improved method and system for relieving the The top portion of vessel 11 is provided with means pressure inside the tank when it exceeds the predetersupplying pressurized fluid such as pressurized air tl".

mined level, which method and system is reliable because to, which means takes the form of air line 15 WhlC air val 1 1 ttin 7 Ch wnich communicates 'th nniunicat th top veslsel 11 We Wa er levgls 1Wlt the air space in the g alve 13 to clear the passa e f fitting 17 on 2 therein ang; ordina y ircumstances and in, Or the relief of ai s Whlch se C negteg thereto bloW-o1f i com e 18 at the Present in- Water ith t ever, noted g 5 11 to h T-fit g i ff g g e i n dim gb P33861158 mitauedmt a quate cross 0 vessel nd rnfiiizi tg grdly along h out ide 81 e Vessel 11 is d ate ccif 'g of air pressure with the b ttOm SS 1 pomt Dproximately even eed of the g Vesse T e lions paced to the c0 umn of ten the 0 e16 :1 arid has standing therein a it h pi 3 the 0 Te lef 1 nt nu us be. water level in Vess 1 11 0 hich orresponds with 1 th 2 V ings controlling th Open 6 ded condult may b scribed as an W111 be Ob -v d that pipe 0 x r e ursting capaci t f fluids end 0f W I h :0 lcates p b d COIl t th top r0 e ed urg ng r ti 0 l F 6 1 is never vessel 11 n b e Wat r I I a p cated inside dea would 0 n air pressure exesedi ti t h gz bottom en Of pip 18 c 12 t F and th the ml fi med level, re, the predetermined level being deter- CXiCllOlly of lcates With a by the gth of pipe 18 the same time, there T veimk k 1 l h ocated 15 is nodanger that the air retained inside vessel 11 will be Vessel 11 e 0W water level 12 in the permitted to escape therefrom by a faulty air valve, which sometimes occurs with prior art systems If that should When pipe 18 is installed as shown in FIG. 1, there is a occur, then vessel 11 would settle again to the bottom.

balanced COlUInn Of Water plus air pressure on the inside This catastrophe cannot occur with this invention because of the pipe just as there is on the inside of tank or vessel 20 there is no air valve which can be stuck in the open posi- As long as this column of water is just suificient for tion.

de-watering vessel 11, the level of the Water and pipe 18 FIG. 2 shows thesystem of this invention installed as will stand at an equal level theiewith However, if there a permanent system in a ship or vessel hull 22 so that air 18 an excess of air pressure applied to vessel 11 above a pressure may be used to de-water ballast tanks or dispredetermined level pipe 18 will be purged of the column charge liquid cargos Wlih llo IlSk of bursting the tanks of water and air pressure inside vessel 11 will be vented FIG. 2 shows that hull 22 18 divided into two separate and therethrough. The predetermined amount of pressure enclosed compartments, each of which has means for supdifferential between the inside of vessel 11 and the outside plying pressurized air thereto in the form of air valve 23 is determined by the length of pipe 18 Since pipe 18 is w ich is connected to an appropriate pressurized an open at the bottom and the surface area on the top of the source. In addition, each of the compartments is prowater column in pipe 18 is the same as the cross-sectional vi-ded near the bottom with water valve 24 which is area at the lower end of pipe 18, the pipe 18 will vent adapted to be manipulated by valve handle 25 from above. instantaneously when the air pressure exceeds the predeter- Valves 24 control the passage of liquids through internal mined differential. conduits 26 the internal ends of which are in communi- As explained above, most tanks or vessels have an intercation with the lower end of the compartments and the nal stress capacity which is large enough to accommodate external ends of which are in communication with the outthe depth of the vessel taking into consideration the specific side of hull 22 In addition each of the compartments is gravity of the liquid which may be placed therein Hence, provided with a blow-off pipe 27, the upper end of which the predetermined amount of the difierential which is esis in communication with the upper end of the compart tablished by pipe 18 is determined by the vertical dimenment and the lower end of which is in communication with sion of the blow-off pipe and the density of the fluid conthe exterior of hull 22 The operations of each of the systained therein. terns shown in FIG. 2 are exactly the same as that shown Pipe 18 can be dimensioned to something greater or less in FIG. I. In other words, pipes 27 correspond to blowthan the tank height. If it is less than the height of the off pipe 18 in FIG. 1. In addition, valves 24 correspond tank, a predetermined amount of fluid can be removed with valve 13in FIG. 1, and air valves 23 correspond with from the tank and when this level is reached, the blow-off air valve 16. will stop the de-watering action at the level of the lower When it is desirable to remove the liquid from the comend of pipe 18. As the end of pipe 18 is made to extend Partments n hull 23 air Pressure 1'5 pp through deeper than vessel 11 and assuming the vessel has this valve 23 to the air space above the liquid level in th degree of bursting stress, vessel 11 can be sunk into deeper compartment of hull 22 which is being unloaded. This water without ingesting Water ballast This sometimes ocair pressure causes the evacuation or displacement of the curs when capsized vessels are being rolled over while liquid therefrom through conduit 25 throu h valve 24 to afloat on the surface and the ingestion of any water therethe exterior of hull 22. However, when air pressure innto would circumvent all of the calculations if the low ide of the compartment exceeds the predetermined level id t k t ok o any b ll t d ring the roll as established by the length of pipe 27 then the air pres- Vessels, such as vessel 11, which have sunk to the bote will be discharged through pipe 27 to the exterior am of a body of water, usually settle into the sand or of the vessel. Hence, there is a built-in safety factor 1nd bottom I Order to remove h a vessel h it which does not permit the internal air pressure to exceed as settled to the bottom, additional breakaway-lift must the ursting capacity of the vessel. The system can be 2 applied in excess of the normal buoyancy required to Used t0 discharge liquid eargos to discharge Water which has been taken on as ballast without danger of e vessel has broken away from the bottom, there is imbursting the h f th vessel.

ediately developed an excess of positive buoyancy which FIGS- A, 313 and 3C Show another embodiment of the uses the vessel to rise to the surface very ra idly. The present invention. In this embodiment, vessel 31 is proeper the vessel is submerged, the greater will be the cd With two generally L-shaped and open ended con- :ssure required to displace the water in the tank dui't means in the form of blow-off pipe 32 which is con- AS V ss l 11 H8 8 a the hydrostatic head or OlliSlde nected to T-fitting 33 which is attached to the top portion 'ssure decreases, the air in the tank must be vented conf Vessel 31 p 32 extends downwardly along the slde lessel 11 Silll has a Water level thef e111 above Valve 13 sel 31 and above water level 34 therein to a point exterior -n the upward movement of vessel 1 begins, the air of vessel 31 and below Water level 34 therein HOteSCaPe through the bottom Valve 13 Even though Vessel 31 is also provided with another open ended de-watering process accelerates as the outside head conduit means in the form of discharge pipe 35 the lower of vessel 31 and extends upwardly through vessel 31 and at right angles over the top of vessel 31. Air pressure is applied to vessel 31 via air line 36 through air valve 37. The operation of the vessel shown in FIG. 3A is in all respects the same as that in FIG. 1. When air pressure inside vessel 31 exceeds the predetermined level determined by the vertical height of the water column in pipe 32 air is vented from the vessel 31 through pipe 32. Meanwhile, the liquid or water in vessel 31 is displaced therefrom through pipe 35 which communicates with the outside of vessel 31 as explained above. Since both pipe 32 and pipe 35 are open ended conduits there is no danger of the passages becoming fouled or clogged as with certain mechanical valves used in the prior art. This embodiment is particularly useful for righting or rolling capsized vessels. FIGS. 3B and 3C show the vessel 31 being rotated to the inverted position which might sometimes occur during salvage procedures. When the 180 rotation is completed as shown in FIG. 3C, pipes 35 and '32 have merely exchanged functions with pipe 35 now acting as the blow-off pipe in case of excess pressure and with pipe 32 acting as the de-watering pipe.

One advantage of this particular embodiment is that the air pocket inside of vessel 31 is retained during the roll. At the same time, if vessel 31 should rise during this rotation it will be relieved of excess air pressures through whichever one of the pipes is then in a position to act as the venting pipe.

However, it will be note-d that there may be a temporary increase in the differential pressure inside and outside the vessel, which increase is equal to the difference between the diagonal distance between the pipe ends and the vertical height of the tank during the roll. If this can be tolerated, either or both of the systems will function during the rotation.

If vessel 31 does not have sufficient stress capacity to tolerate this increased pressure differential during rolling, then the outside legs of the de-watering pipe and the blowoff pipe can be shortened as shown in FIG. 4.

There tank or vessel 31 is shown having dual conduits in the form of pipes 41 and 42'installed therein. Pipe 41 generally corresponds with pipe 35 shown in FIG. 3A and pipe 42 generally corresponds with pipe 32 shown in FIG. 3A. However, by having the shortened legs as shown, during the roll of vessel 31 as described with respect to FIGS. 3A, 3B and 3C, the internal stress capacity of the vessel 31 will not be exceeded since vertical dimensions h are equal to the height of tank 31 when in a horizontal position. Hence, the internal stress capacity of vessel 31 would never be exceeded during the rolling operation assuming that the stress capacity was equal to the hull depth or the vessel depth in the horizontal position. Here again, the air inside of vessel 31 is entrapped during the roll, yet there is positive assurance that air pressure inside vessel 31 will not exceed the bursting capacity of the vessel. The vertical dimensions of the water columns in pipes 41 and 42 could never exceed the height of the tank, which is the distance it and, hence, the bursting capacity would never be exceeded.

It will be observed that the art has been provided with a new and novel system and method for discharging liquids from vessels in a safe and convenient manner without danger of bursting the vessel. Moreover, the system and method is adaptable for salvaging submerged tanks with similar assurance that the vessels will not burst during the salvaging operation.

Modifications may be made in the invention as particularly described without departing from the scope of the invention. Accordingly, the foregoing description is to be construed illustratively only and is not to be construed as a limitation upon the invention as defined in the following claims.

What is claimed is:

1. The method of discharging liquid from a liquid 6 containing vessel immersed in an immersing medium, said method comprisng the steps of:

introducing a pressurized fluid into the vessel at a pressure sufiicent to displace the liquid therefrom; displacing the liquid from the vessel by application of the pressurized fluid; and

relieving the pressure inside the vessel when the pressure differential inside and outside the vessel exceeds a predetermined level by venting the pressurized fluid from a first point located inside the vessel and above the liquid level therein to a second point located exteriorly of the vessel and spaced below the first point a distance which is suflicient to cause the venting to occur when the pressure differential exceeds the predetermined level.

2. The method as claimed in claim 1 wherein:

the pressurized fluid has a lower specific gravity than the liquid being displaced and is immiscible therewith.

3. The method of discharging water from a Water containing vessel immersed in a body of Water, comprising the steps of:

introducing a pressurized gas into the vessel at a pressure sufficient to displace the liquid therefrom; displacing the water from the vessel by application of the pressurized gas; and

relieving the pressure inside the vessel when the pressure differential inside the vessel exceeds the pressure outside the vessel by a predetermined amount by venting the pressurized gas from the vessel through a path starting at a first point located inside the vessel and above the water level therein and ending at a second point located exteriorly of the vessel and spaced below the first point and below the liquid level inside the vessel a distance which is sufficient to cause the venting to occur when the pressure differential exceeds the predetermined amount.

4. The method of raising a liqud containing vessel immersed in a body of liquid, comprising the steps of:

applying pressurized gas to the inside of the vessel;

forcing the liquid from the vessel by application of the pressurized gas; and

relieving the pressure inside the vessel as the vessel rises causing the pressure differential inside and outside the vessel to exceed a predetermined level by venting the gas from a first point located inside the vessel and above the liquid level therein to a second point located exteriorly of the vessel and below the liquid level therein.

'5. The method of raising an enclosed liquid containing vessel immersed in a body of liquid, comprising the steps of:

applying pres-surized air to the inside of the vessel at a sufficient pressure to displace the liquid therefrom; displacing the liquid from the vessel by the application of the pressurized air; and

relieving the pressure inside the vessel when the pressure differential between the inside of the vessel and outside of the vessel exceeds the safe internal stress capacity of the vessel by venting air from a first point located inside the vessel and above the liquid level therein to a second point located exteriorly of the vessel and below the liquid level in the vessel.

6. In a system for discharging a liquid from a liquid containing vessel immersed in an immersing medium, said system comprising:

means for introducing a pressurized fluid into the vessel to displace the liquid therefrom;

outlet means for discharging liquid from the vessel;

and

conduit means associated with the vessel for relieving the pressure inside the vessel when the pressure differential inside and outside the vessel exceeds a predetermined amount, with the conduit means communciating between a first point located inside the vessel and above the liquid level therein and a second point located exteriorly of the vessel and spaced below the liquid level inside the vessel a distance which is adapted to maintain the predetermined pressure differential.

7. The system as claimed in claim 6 wherein:

the means for introducing a pressurized fluid into the vessel is adapted to introduce a pressurized gas.

8. In a system for discharging a liquid from a liquid containing vessel immersed in an immersing medium, the system comprising:

means for introducing a pressurized gas into the vessel at sutficient pressure to displace the liquid therefrom;

outlet means for discharging liquid from the vessel upon application of the pressurized gas; and

pressure relieving means associated with the vessel for relieving the pressure inside the vessel when the pressure inside the vessel exceeds the pressure outside the vessel by a predetermined amount, the pressure relieving means including open ended conduit means communicating between a first point located inside the vessel and above the fluid level therein and a second point located exteriorly of the vessel and spaced below the liquid level inside the vessel a distance which is adapted to maintain the predetermined pressure differential.

9. The system claimed in claim 8 wherein:

the outlet means for discharging liquid from the vessel includes a conduit communicating from a third point inside the vessel and near the bottom thereof to a fourth point located outside the vessel.

10. The system as claimed in claim 8 wherein:

the open ended conduit means is adapted to normally contain a column of liquid therein, the top level of which is generally level with the fluid level inside the vessel, which liquid column is blown out when the inside-outside pressure differential exceeds the predetermined amount.

11. In a system for discharging a liquid from an enclosed liquid containing vessel immersed in a liquid, the system comprising:

means for introducing a pressurized gas into the vessel at sufficient pressure to displace the liquid therefrom;

a first generally L-shaped and open ended conduit communicating with the inside of the vessel at a point near the top side thereof and extending downwardly therefrom and under the vessel;

a second generally L-sha-ped and open ended conduit communicating with the inside of the vessel at another point near the bottom side thereof and extend ing upwardly therefrom and over the vessel;

whereby the first conduit acts as the liquid dispensing outlet and the second conduit acts as the excess pressure relief outlet in the upright position and said conduits exchange functions when the vessel is inverted. 12. A vessel adapted for ready salvage after having been submerged by flooding with water, comprising:

an enclosed tank; means for applying pressurized gas to the inside of the tank vat a sufiicient pressure to displace the water therefrom; means for discharging water from the tank upon application of the pressurized gas; and open ended conduit means communicating from a first point located inside the tank and above the water level therein to a second point located outside the tank and below the liquid level in the tank, with the distance below being selected to maintain a predetermined pressure differential between the inside and outside of the tank, whereby pressurized gas is discharged from the tank through the conduit means when the inside and outside pressure differential exceeds the predetermined level. 13. A vessel adapted for ready salvage after having been submerged by flooding with water, comprising:

a plurality of enclosed tanks, each of said tanks having:

means for applying pressurized air to the inside thereof at a pressure sufficient to displace the water therefrom; means for discharging water therefrom upon application of the pressurized air; and open ended conduit means communicating between a first point located inside the tank and above the water level therein and a second point located outside the tank and below the water level therein, with the distance below being selected to maintain a predetermined pressure differential between the inside and the outside of the tank, whereby pressurized air is discharged from the tank through the conduit means when the inside and outside pressure differential exceeds a predetermined level. 14. The vessel as claimed in claim 12 wherein: each of the conduit means is adapted to normally have a column of water standing therein, the top level of which is generally level with the water level in the tank associated therewith, which water column is blown out when the inside-outside pressure differential exceeds the predetermined amount.

References Cited by the Examiner UNITED STATES PATENTS 2,989,069 6/1961 Nixon 137-25l MILTON BUCHLER, Primary Examiner.

ANDREW H. FARRELL, Examiner.

Claims (1)

1. THE METHOD OF DISCHARGING LIQUID FROM A LIQUID CONTAINING VESSEL IMMERSED IN AN IMMERSING MEDIUM, SAID METHOD COMPRISING THE STEPS OF: INTRODUCING A PRESSURIZED FLUID INTO THE VESSEL AT A PRESSURE SUFFICIENT TO DISPLACE THE LIQUID THEREFROM; DISPLACING THE LIQUID FROM THE VESSEL BY APPLICATION OF THE PRESSURIZED FLUID; AND RELIEVING THE PRESSURE INSIDE THE VESSEL WHEN THE PRESSURE DIFFERENTIAL INSIDE AND OUTSIDE THE VESSEL EXCEEDS A PREDETERMINED LEVEL BY VENTING THE PRESSURIZED FLUID FROM A FIRST POINT LOCATED INSIDE THE VESSEL AND ABOVE THE LIQUID LEVEL THEREIN TO A SECOND POINT LOCATED EXTERIORLY OF THE VESSEL AND SPACED BELOW THE FIRST POINT A DISTANCE WHICH IS SUFFICIENT TO CAUSE THE VENTING TO OCCUR WHEN THE PRESSURE DIFFERENTIAL EXCEEDS THE PREDETERMINED LEVEL.

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