CA1136495A - Spill overflow prevention system for tanker vessels - Google Patents
Spill overflow prevention system for tanker vesselsInfo
- Publication number
- CA1136495A CA1136495A CA000375534A CA375534A CA1136495A CA 1136495 A CA1136495 A CA 1136495A CA 000375534 A CA000375534 A CA 000375534A CA 375534 A CA375534 A CA 375534A CA 1136495 A CA1136495 A CA 1136495A
- Authority
- CA
- Canada
- Prior art keywords
- trunk line
- cargo
- retention tank
- petroleum products
- compartments
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Landscapes
- Filling Or Discharging Of Gas Storage Vessels (AREA)
Abstract
SPILL OVERFLOW PREVENTION SYSTEM FOR TANKER VESSELS
ABSTRACT
An improved spill overflow prevention system for tanker vessels comprising a longitudinally disposed trunk line, branch lines coupled at one end to the trunk line and at the other end to the cargo compartments of the vessel, valves coupled to the branch lines inter-mediate the ends thereof for permitting the free flow of fluid chemical and petroleum products from the cargo compartments to the trunk line through the branch lines, and a retention tank disposed in the vessel and coupled to the trunk line for receiving fluid chemical and petro-leum products from the trunk line. Fluid chemical and petroleum products overflowing from the cargo compart-ments of the vessel are directed from the compartments through the branch lines and trunk line to the retention tank thereby preventing overflow of the products exter-nally of the compartments. The branch and trunk lines are dimensioned so as to prevent any overpressurization of the compartments during an overflow.
ABSTRACT
An improved spill overflow prevention system for tanker vessels comprising a longitudinally disposed trunk line, branch lines coupled at one end to the trunk line and at the other end to the cargo compartments of the vessel, valves coupled to the branch lines inter-mediate the ends thereof for permitting the free flow of fluid chemical and petroleum products from the cargo compartments to the trunk line through the branch lines, and a retention tank disposed in the vessel and coupled to the trunk line for receiving fluid chemical and petro-leum products from the trunk line. Fluid chemical and petroleum products overflowing from the cargo compart-ments of the vessel are directed from the compartments through the branch lines and trunk line to the retention tank thereby preventing overflow of the products exter-nally of the compartments. The branch and trunk lines are dimensioned so as to prevent any overpressurization of the compartments during an overflow.
Description
--`` 1136495 SPILL OVERFLOW PREVENTION SYSTEM FOR TANKER VESSELS
The present invention relates to an auto-matic system for preventing external cargo spillage from tanker vessels resulting from the overflow of cargo from the cargo compartments of the vessel during loading ~here-of.
Presently~cargo~comprising fluid ohemical and petroleum products~,~;such as,~for;examp~le, oil, is~loàded into tanker vessels~by~means of~transfer hoses and aargo pipelines which~are~coupled~to~lnléts communicative~with the cargo compartments of~the~ves8el. It~sometimqs oc-curs during loading;~or transfer~of cargo that the fluid and chemical products~continue~to flow~after the~dompart-~
ments~are~full.~ As~a~rèsult,~càrgo~overflows through~ul~
lage~openings,~gas~vents~or;~other deck apertures communi-15 ~ cative~with~the co~partm~nts~, over~the~dèck~of the~ves9el~
and~into~the water, ther by~causi ;a Jplll a d prod cin water contamination,~atmospheric~pollution, as well as a fire~ and~explos~io~hazard. ~
Cargo spill8 are~the n sult of a variety of t 20 ~ ~eaUses.~ One,~;for~èxample,~ls négligenQe~on the part of personnel in charge~of loàding~the cargo compartments of ; ` :
, : . :
: : :
-: . , .
~ 113S~9~
the vessel. ~nother is a faulty loading valve, for example, a leaky valve or a foreign substance wedged under the valve gate. Others are a leaking line under pressure within the cargo compartments; an increase, without notice, of the vessel loading rate; and a broken valve reach rod or other control segment during closing of an inlet valve after a cargo compartment has been filled. Such cargo overflows can cause significant pol-lution of coastal waterways, particularly when the cargo being loaded is crude oil. For example, depending upon the size of the vessel and the flow rate of the cargo during loading and the duration of the overflow before it is discovered, anywhere from several barrels to several thousand barrelo of oil may be lost from a single cargo spill caused by an over10w.
Cargo tank overflll aontrol systems have been devised to prevent overflows~from cargo compartments of a - ~ tanker vessel during loading. High level alarms and con-tinuous tank cargo level indicators, for example, are used to monitor cargo~tank }~evels ln a vessel during loading.
While such devlces are helpful, they are sub~ect to mal-functions, are dependent on human monitors, and do not automatically prevent pollutlon, and these characteristics make such devices unacaeptabIe for vessels carrying car-goes such as crude oil having the potential of creating '.
;.
'; ~ ' ~ .: ' .
: ' ' , .3~i4~35 serious environmental pollution in coastal waterways andports in the event of spillage from the vessel caused by an overflow during loading. Remotely-actuated, quick-closing shut off valves have been used in such vessels to help reduce overflows but it has been found that such valves can create excessive surge pressures in the cargo transfer hoses and pipelines used to load the vessel which are great enough to rupture the hoses and line thereby re-sulting in the spillage of cargo. Such valves are, more-over, still dependent on human attention for effectiveoperation.
It is therefore an object of the present inven-tion to provide an automatic spill overflow prevention system for tanker vessels which overcomes the aforemen-tioned disadvantages of prior tank fill indicators andoverflow handling systems and automatically prevents the spillage of fluid chemical and petroleum products during ~ , ~
~ loading operation:s~or cargo transfer operations in the :~ vessel without~the danger of causing a rupture of the 20~ hoses and pipel~ines used to load the vessel or the bulk-heads of the vessel.
It is also an ob~ect of the present invention to provide an improved spill overflow prevention system for tanker vessels which will reduce the pollution of the natural environment, partlcularly the pollution of coastal ::
. .
.... ~ r ~ ?~ ~ c ~ .
': '.: :. ' ~ `
' ~13f~5 and intercoastal waterway areas and ports.
These and other objects of the invention are achieved in a tanker vessel for the transportation of fluid chemical and petroleum products in water. The vessel includes a hull comprising a bottom and sides, a top deck, a plurality of watertight cargo compartments disposed within the hull between the top deck and the hull bottom for receiving the fluid chemical and petroleum pro-ducts, and means coupled to the cargo compartments for filling the compartments with the fluid chemical and petroleum products. The improvement of the invention com-prises longitudinally disposed trunk line means, branch line means coupled at one end to the trunk line means and at the other end to the cargo compartments, valve means coupled to the branch line means~lntermediate the~ends thereof for permitting the free flow of fluid chemical and petroleum products from the cargo compartments to the trunk line means through the branch line means, the branch ; line means being dimensioned so as to prevent overpressuri-zation of the cargo compartments during the flow of fluid chemical and petroleum products from the compartments to the trunk line means, and retention tank means disposed in the vessel and coupled to the trunk line means for receiv-ing fluid chemical and petroleum products from the trunk line means. Fluid chemical and petroleum products over-' :
~' 113~i4~5 flowing from the cargo compartments during filling there-of are directed from the cargo compartments through the branch line means and the trunk line means to the reten-tion tank means thereby preventing the spillage of the fluid chemical and petroleum products externally of the cargo compartments.
The improved spill overflow system of the present invention will significantly reduce safety haz-ards, cargo loss, and the pollution of coastal waterways and ports caused by tank overflows during loading opera-tions, transfers, discharge or cargo expansion in a tan-ker vessel. This is achieved by utilizing a retention tank, specifically one or more empty tanks, such as a cofferdam, void space or ballast tank or other suitable vessel space, as a plenum, and directing any overflows from the cargo compartments into such a retention tank.
These and other novel features and advantages of the present invention will be described in greater de-tail in the following detailed description.
fn~the drawings, wherein similar reference numerals denote similar elements throughout the several views thereof:
FIGURE 1 is a perspeative view, partially in cross-section, of a ta~ker vessel incorporating an im-proved spill overflow prevention system constructed ac-:.
' ,. ' ' ', ' '. ~ . :
~ 113~495 cording to the present invention;
FIGURE 2 is a partial, cross-sectional view of the improved spill overflow prevention system illus-trated in FIGURE 1 showing the construction of the trunk line, branch line and control valve of the system; and FIGURE 3 is a partial, cross-sectional view of the improved spill overflow prevention system illus-trated in FIGURE 1 showing the construction of the reten-tion tank.
1~ Referring now to the drawings, there is shown a tanker vessel generally identified by the reference numeral 10 which lncludes a hull comprising a bottom 11 and sides 12, a top or main deck 13, and a plurality of watertight cargo compartments 14.~ The cargo compartments are disposed within the hull between top deck 13 and hull bottom 11 for receiving cargo comprising fluid ohemioal and petroleum products, for example~,~ crude oil, from a :~ land storage tank 15. Cargo expansion trunks 16 are cou-~ ~.
~: pled to and open downwardly into each of oargo compart--20 ments 14. A cargo pipeline 17 i8: ooupled to each of the : : cargo compartments 14 for filling the compartments with cargo from land storage tank 15.
~:~. . Vessel 10 inoludes a longitudinal trunk line ~; 18, which can be dis~osed either above or below top deok ~25 13, and a plurality:of branch lines 19 which are coupled ~ ~ .
' ' ' ~ '' , ~ ' ' ' ;' :
. ' ', ' ,'., ' '.
'''I ' ' . ' ', '; ~ ~ ' , ' . ~
,` :' ' ' ' ' , " ' ' ' '` ~ :
~ ~3~5 at one end to trunk line 18 and at the other end to cargo expansion trunks 16. A plurality of valves 20, which may comprise either non-return clapper valves, weighted or spring-controlled to produce the required back pressure for vapor venting, or positive type closure valves, the latter preferably being butterfly-type valves, are coupled to the branch lines 19 intermediate the ends thereof for permitting the free flow of fluid chemical and petroleum products, i.e., the liquid cargo, from cargo expansion trunks 16 to trunk line 18 through branch lines 19. If non-return clapper valves are used, the valves permit the free flow of the liquid cargo only from cargo expansion trunks 16 to trunk line 18 through branch lines 19. A cargo retention tank 21, which may comprise either a wing tank or a plurality of interconnected tanks of the vessel, is coupled to trunk line 18 for receiving cargo from the trunk line. An overflow pipe 22 is disposed with-in the retention tank 21 for directing the cargo overflow within the retention tank and has an enlarged opening 23 at one end thereof which is disposed below the end of trunk line 18. The latter extends downwardly and opens into the retention tank 21 ~ust below top deck 13. ~he en-larged opening 23 of pipe 22 receives cargo overflow from trunk line 18 and is spaced slightly apart from the end of the trunk line in tank 21 in order to permit gases, for .
.
.
~-` 113~4~S
example, hydrocarbon gases and the like to escape from the trunk line into the retention tank 21. A plurality of apertures may also be disposed about the periphery of opening 23 to permit gases to escape into retention tank 21. The retention tank is provided with an exhaust vent 24 which includes a flame screen 25 and a pressuretvacuum relief valve 26 for venting gases from the retention tank to the atmosphere. Gases are vented from the cargo compartments 14 to the atmosphere during filling of the compartments through trunk line 18 and branch lines 19 to retention tank 21. A plurality of bypass lines 27 are coupled to branch lines 19 intermediate the ends thereof and in parallel relationship therewith, each including a pressure/vacuum relief valve 28, which preferably com-prises a closed type pressure/vacuum relief valve, coupled .
to the bypass line intermediate its ends, for ventinggases from cargo~compartments 14 to retention tank 21 through trunk line l8 and branch lines 19 when valves 20 are positive type closure valves and are closed, i.e., during all operations on the vessel except when filling any cargo compartments or tranæferring~cargo between the com-partments. When valves 20 comprise non-return clapper valves, the bypass lines 27 and valves 28 permit vacuum relief in the cargo compartments 14. It should be noted that the bypass lines 27 are not required if the vessel is ~ .
:: ~ .
-, . : .
. .
: `
' ' ' : ' : ' , ' '; ~ ' ' ` . , ': : ~
3~i~95 retrofitted with the spill overflow prevention systemof the invention and already has an existing venting system which is retained.
Branch lines l9 are dimensioned, i.e., have a diameter which is large enough to prevent overpressuri-zation of the cargo compartments dur1ng an overflow while loading or transferring cargo. The term "overpressuriza-tion" means a pressure build-up in the cargo compartments due to the pumping of cargo into the compartments at high pressure which would cause structural damage to the bulk-heads of the vessel. Such a pressure build-up is re-lieved by sizing the branch lines l9 so that the lines have a diameter which is greater than the diameter of the filling lines or plpes us-d to load the compartments to such an extent that the pressure~in the cargo compartments ls reduced to a~lével~below the~maximum the vess;el bulk-~ heads can withatand before sustaining damage. It should : ~ ~ be~noted that~both~trunk llne~18~and branch lines l9 may comprise rectangular or~square-shaped ducts, or partially 20~ ~ cir~ular pipes,~as~we11 as~the~circular pipes illustrated in the drawings, and aan be disposed either above or below the deck of the vessel. The diameter of trunk line 18, as a general rule, will always be;aonsiderably greater than that of the branch~lines 19 and for that reason usually is not a faotor in overpressurization of the aargo com-: :
:
., ;: ~
.
'~
' ' ', ' ~ . : .
' 1~..3~95 partments 14. If,however, for some reason a back pres-sure were produced by the trunk line for example if the trunk line had a diameter which was less than that of the branch lines, this pressure would have to be considered along with the pressure produced by the branch lines in determining the dimensions of the lines which will keep the pressure in the compartments 14 below the maximum al-lowable overpressure.
: A line flow alarm 29 is coupled in series with trunk line 18 for indiaating the flow of cargo in the trunk line. In addition, retention tank 21 preferably comprises a side compartment of vessel 10 in order to provide an ad-ditional indication of the flow of cargo through the trunk line and of an overflow by causing the vessel to heel over slightly. This provides an:additional level of protection : in the event that the~l:ine~flow~alarm fails to indicate and/or crewmen working on the vessel are inattentive or are not present and fail to detect an overflow from the com- :
partments through~the trunk line.~ ~
In operation,~in:the~:event that the volume of cargo loaded into one~or more of the cargo compartments of the vessel exaeeds the aapacity of the compartments and :; overflows, the excess~aargo is direated through cargo ex-: pansion trunk 16 and branch line 19 to the trunk line 18 and flows throuqh the trunk line into retention tank 21.
~:
.
. ~ .
., ~ . ... . . .
: - . .. ~ . ~ . ...
.:
-.
If valves 20 comprise positive-type closure valves, the valves are opened prior to commencem~nt of the loading operation. If non-return clapper valves are used, the valves will automatically open when an overflow occurs.
The flow through the trunk line 18 is indicated by the flow alarm 29, which produces an audible and/or visible alarm. Cargo entering the retention tank is received by enlarged opening 23 of overflow pipe 22 and is directed by the pipe within the tank to the tank bottom. Gases pre-sent in cargo compartments 14, for example, hydrocarbongases produced by petroleum products, are expelled from the compartments during loading or cargo transfer and flow through branch lines 19 into trunk line 18 and es-cape from the end of the trunk line in retention tank 21.
The gases are then vented under pressure to the atmosphere through exhaust vent 24. The exhaust vent 24 is prefer-ably designed so that it terminates at its open upper end at a level above the vessel's deck which is well clear of personnel areas and any hazard of ignition on the vessel.
It should be noted that a closed tank loading system is re-quired during loading or transfer operation- on the vessel.
This system can be either an automatic or manual closed ullage system or a simple glass visor having an internal wiper device fitted in eaoh ullage opening. The spill overflow system of the present invention may also be used ., .
for bunker tanks, chemic,al tanks, etc., to prevent over-flow loss and hazard in the same manner as with cargo compartments.
In the foregoing specification, the invention has been described with reference to specific exemplary embodiments thereof. It will, however, be evident that various modifications and changes may be made thereunto without departing from the broader spirit and scope of the invention as set forth in the appended claims.~ The speci-fication and drawings are, aocordingly, to~be~regarded ln ;~ ~ an illustrative`rather than in a~restrictive sense.
,` . ~
'. :
~ : ' `
r -': ' .
' '~ ! , : `
:' . ' " ' ; ' ''' ', ' ' ' ' ' ' . ' ' ~ ~
' ' . '.
' " .
.. . ' ': . .` '
The present invention relates to an auto-matic system for preventing external cargo spillage from tanker vessels resulting from the overflow of cargo from the cargo compartments of the vessel during loading ~here-of.
Presently~cargo~comprising fluid ohemical and petroleum products~,~;such as,~for;examp~le, oil, is~loàded into tanker vessels~by~means of~transfer hoses and aargo pipelines which~are~coupled~to~lnléts communicative~with the cargo compartments of~the~ves8el. It~sometimqs oc-curs during loading;~or transfer~of cargo that the fluid and chemical products~continue~to flow~after the~dompart-~
ments~are~full.~ As~a~rèsult,~càrgo~overflows through~ul~
lage~openings,~gas~vents~or;~other deck apertures communi-15 ~ cative~with~the co~partm~nts~, over~the~dèck~of the~ves9el~
and~into~the water, ther by~causi ;a Jplll a d prod cin water contamination,~atmospheric~pollution, as well as a fire~ and~explos~io~hazard. ~
Cargo spill8 are~the n sult of a variety of t 20 ~ ~eaUses.~ One,~;for~èxample,~ls négligenQe~on the part of personnel in charge~of loàding~the cargo compartments of ; ` :
, : . :
: : :
-: . , .
~ 113S~9~
the vessel. ~nother is a faulty loading valve, for example, a leaky valve or a foreign substance wedged under the valve gate. Others are a leaking line under pressure within the cargo compartments; an increase, without notice, of the vessel loading rate; and a broken valve reach rod or other control segment during closing of an inlet valve after a cargo compartment has been filled. Such cargo overflows can cause significant pol-lution of coastal waterways, particularly when the cargo being loaded is crude oil. For example, depending upon the size of the vessel and the flow rate of the cargo during loading and the duration of the overflow before it is discovered, anywhere from several barrels to several thousand barrelo of oil may be lost from a single cargo spill caused by an over10w.
Cargo tank overflll aontrol systems have been devised to prevent overflows~from cargo compartments of a - ~ tanker vessel during loading. High level alarms and con-tinuous tank cargo level indicators, for example, are used to monitor cargo~tank }~evels ln a vessel during loading.
While such devlces are helpful, they are sub~ect to mal-functions, are dependent on human monitors, and do not automatically prevent pollutlon, and these characteristics make such devices unacaeptabIe for vessels carrying car-goes such as crude oil having the potential of creating '.
;.
'; ~ ' ~ .: ' .
: ' ' , .3~i4~35 serious environmental pollution in coastal waterways andports in the event of spillage from the vessel caused by an overflow during loading. Remotely-actuated, quick-closing shut off valves have been used in such vessels to help reduce overflows but it has been found that such valves can create excessive surge pressures in the cargo transfer hoses and pipelines used to load the vessel which are great enough to rupture the hoses and line thereby re-sulting in the spillage of cargo. Such valves are, more-over, still dependent on human attention for effectiveoperation.
It is therefore an object of the present inven-tion to provide an automatic spill overflow prevention system for tanker vessels which overcomes the aforemen-tioned disadvantages of prior tank fill indicators andoverflow handling systems and automatically prevents the spillage of fluid chemical and petroleum products during ~ , ~
~ loading operation:s~or cargo transfer operations in the :~ vessel without~the danger of causing a rupture of the 20~ hoses and pipel~ines used to load the vessel or the bulk-heads of the vessel.
It is also an ob~ect of the present invention to provide an improved spill overflow prevention system for tanker vessels which will reduce the pollution of the natural environment, partlcularly the pollution of coastal ::
. .
.... ~ r ~ ?~ ~ c ~ .
': '.: :. ' ~ `
' ~13f~5 and intercoastal waterway areas and ports.
These and other objects of the invention are achieved in a tanker vessel for the transportation of fluid chemical and petroleum products in water. The vessel includes a hull comprising a bottom and sides, a top deck, a plurality of watertight cargo compartments disposed within the hull between the top deck and the hull bottom for receiving the fluid chemical and petroleum pro-ducts, and means coupled to the cargo compartments for filling the compartments with the fluid chemical and petroleum products. The improvement of the invention com-prises longitudinally disposed trunk line means, branch line means coupled at one end to the trunk line means and at the other end to the cargo compartments, valve means coupled to the branch line means~lntermediate the~ends thereof for permitting the free flow of fluid chemical and petroleum products from the cargo compartments to the trunk line means through the branch line means, the branch ; line means being dimensioned so as to prevent overpressuri-zation of the cargo compartments during the flow of fluid chemical and petroleum products from the compartments to the trunk line means, and retention tank means disposed in the vessel and coupled to the trunk line means for receiv-ing fluid chemical and petroleum products from the trunk line means. Fluid chemical and petroleum products over-' :
~' 113~i4~5 flowing from the cargo compartments during filling there-of are directed from the cargo compartments through the branch line means and the trunk line means to the reten-tion tank means thereby preventing the spillage of the fluid chemical and petroleum products externally of the cargo compartments.
The improved spill overflow system of the present invention will significantly reduce safety haz-ards, cargo loss, and the pollution of coastal waterways and ports caused by tank overflows during loading opera-tions, transfers, discharge or cargo expansion in a tan-ker vessel. This is achieved by utilizing a retention tank, specifically one or more empty tanks, such as a cofferdam, void space or ballast tank or other suitable vessel space, as a plenum, and directing any overflows from the cargo compartments into such a retention tank.
These and other novel features and advantages of the present invention will be described in greater de-tail in the following detailed description.
fn~the drawings, wherein similar reference numerals denote similar elements throughout the several views thereof:
FIGURE 1 is a perspeative view, partially in cross-section, of a ta~ker vessel incorporating an im-proved spill overflow prevention system constructed ac-:.
' ,. ' ' ', ' '. ~ . :
~ 113~495 cording to the present invention;
FIGURE 2 is a partial, cross-sectional view of the improved spill overflow prevention system illus-trated in FIGURE 1 showing the construction of the trunk line, branch line and control valve of the system; and FIGURE 3 is a partial, cross-sectional view of the improved spill overflow prevention system illus-trated in FIGURE 1 showing the construction of the reten-tion tank.
1~ Referring now to the drawings, there is shown a tanker vessel generally identified by the reference numeral 10 which lncludes a hull comprising a bottom 11 and sides 12, a top or main deck 13, and a plurality of watertight cargo compartments 14.~ The cargo compartments are disposed within the hull between top deck 13 and hull bottom 11 for receiving cargo comprising fluid ohemioal and petroleum products, for example~,~ crude oil, from a :~ land storage tank 15. Cargo expansion trunks 16 are cou-~ ~.
~: pled to and open downwardly into each of oargo compart--20 ments 14. A cargo pipeline 17 i8: ooupled to each of the : : cargo compartments 14 for filling the compartments with cargo from land storage tank 15.
~:~. . Vessel 10 inoludes a longitudinal trunk line ~; 18, which can be dis~osed either above or below top deok ~25 13, and a plurality:of branch lines 19 which are coupled ~ ~ .
' ' ' ~ '' , ~ ' ' ' ;' :
. ' ', ' ,'., ' '.
'''I ' ' . ' ', '; ~ ~ ' , ' . ~
,` :' ' ' ' ' , " ' ' ' '` ~ :
~ ~3~5 at one end to trunk line 18 and at the other end to cargo expansion trunks 16. A plurality of valves 20, which may comprise either non-return clapper valves, weighted or spring-controlled to produce the required back pressure for vapor venting, or positive type closure valves, the latter preferably being butterfly-type valves, are coupled to the branch lines 19 intermediate the ends thereof for permitting the free flow of fluid chemical and petroleum products, i.e., the liquid cargo, from cargo expansion trunks 16 to trunk line 18 through branch lines 19. If non-return clapper valves are used, the valves permit the free flow of the liquid cargo only from cargo expansion trunks 16 to trunk line 18 through branch lines 19. A cargo retention tank 21, which may comprise either a wing tank or a plurality of interconnected tanks of the vessel, is coupled to trunk line 18 for receiving cargo from the trunk line. An overflow pipe 22 is disposed with-in the retention tank 21 for directing the cargo overflow within the retention tank and has an enlarged opening 23 at one end thereof which is disposed below the end of trunk line 18. The latter extends downwardly and opens into the retention tank 21 ~ust below top deck 13. ~he en-larged opening 23 of pipe 22 receives cargo overflow from trunk line 18 and is spaced slightly apart from the end of the trunk line in tank 21 in order to permit gases, for .
.
.
~-` 113~4~S
example, hydrocarbon gases and the like to escape from the trunk line into the retention tank 21. A plurality of apertures may also be disposed about the periphery of opening 23 to permit gases to escape into retention tank 21. The retention tank is provided with an exhaust vent 24 which includes a flame screen 25 and a pressuretvacuum relief valve 26 for venting gases from the retention tank to the atmosphere. Gases are vented from the cargo compartments 14 to the atmosphere during filling of the compartments through trunk line 18 and branch lines 19 to retention tank 21. A plurality of bypass lines 27 are coupled to branch lines 19 intermediate the ends thereof and in parallel relationship therewith, each including a pressure/vacuum relief valve 28, which preferably com-prises a closed type pressure/vacuum relief valve, coupled .
to the bypass line intermediate its ends, for ventinggases from cargo~compartments 14 to retention tank 21 through trunk line l8 and branch lines 19 when valves 20 are positive type closure valves and are closed, i.e., during all operations on the vessel except when filling any cargo compartments or tranæferring~cargo between the com-partments. When valves 20 comprise non-return clapper valves, the bypass lines 27 and valves 28 permit vacuum relief in the cargo compartments 14. It should be noted that the bypass lines 27 are not required if the vessel is ~ .
:: ~ .
-, . : .
. .
: `
' ' ' : ' : ' , ' '; ~ ' ' ` . , ': : ~
3~i~95 retrofitted with the spill overflow prevention systemof the invention and already has an existing venting system which is retained.
Branch lines l9 are dimensioned, i.e., have a diameter which is large enough to prevent overpressuri-zation of the cargo compartments dur1ng an overflow while loading or transferring cargo. The term "overpressuriza-tion" means a pressure build-up in the cargo compartments due to the pumping of cargo into the compartments at high pressure which would cause structural damage to the bulk-heads of the vessel. Such a pressure build-up is re-lieved by sizing the branch lines l9 so that the lines have a diameter which is greater than the diameter of the filling lines or plpes us-d to load the compartments to such an extent that the pressure~in the cargo compartments ls reduced to a~lével~below the~maximum the vess;el bulk-~ heads can withatand before sustaining damage. It should : ~ ~ be~noted that~both~trunk llne~18~and branch lines l9 may comprise rectangular or~square-shaped ducts, or partially 20~ ~ cir~ular pipes,~as~we11 as~the~circular pipes illustrated in the drawings, and aan be disposed either above or below the deck of the vessel. The diameter of trunk line 18, as a general rule, will always be;aonsiderably greater than that of the branch~lines 19 and for that reason usually is not a faotor in overpressurization of the aargo com-: :
:
., ;: ~
.
'~
' ' ', ' ~ . : .
' 1~..3~95 partments 14. If,however, for some reason a back pres-sure were produced by the trunk line for example if the trunk line had a diameter which was less than that of the branch lines, this pressure would have to be considered along with the pressure produced by the branch lines in determining the dimensions of the lines which will keep the pressure in the compartments 14 below the maximum al-lowable overpressure.
: A line flow alarm 29 is coupled in series with trunk line 18 for indiaating the flow of cargo in the trunk line. In addition, retention tank 21 preferably comprises a side compartment of vessel 10 in order to provide an ad-ditional indication of the flow of cargo through the trunk line and of an overflow by causing the vessel to heel over slightly. This provides an:additional level of protection : in the event that the~l:ine~flow~alarm fails to indicate and/or crewmen working on the vessel are inattentive or are not present and fail to detect an overflow from the com- :
partments through~the trunk line.~ ~
In operation,~in:the~:event that the volume of cargo loaded into one~or more of the cargo compartments of the vessel exaeeds the aapacity of the compartments and :; overflows, the excess~aargo is direated through cargo ex-: pansion trunk 16 and branch line 19 to the trunk line 18 and flows throuqh the trunk line into retention tank 21.
~:
.
. ~ .
., ~ . ... . . .
: - . .. ~ . ~ . ...
.:
-.
If valves 20 comprise positive-type closure valves, the valves are opened prior to commencem~nt of the loading operation. If non-return clapper valves are used, the valves will automatically open when an overflow occurs.
The flow through the trunk line 18 is indicated by the flow alarm 29, which produces an audible and/or visible alarm. Cargo entering the retention tank is received by enlarged opening 23 of overflow pipe 22 and is directed by the pipe within the tank to the tank bottom. Gases pre-sent in cargo compartments 14, for example, hydrocarbongases produced by petroleum products, are expelled from the compartments during loading or cargo transfer and flow through branch lines 19 into trunk line 18 and es-cape from the end of the trunk line in retention tank 21.
The gases are then vented under pressure to the atmosphere through exhaust vent 24. The exhaust vent 24 is prefer-ably designed so that it terminates at its open upper end at a level above the vessel's deck which is well clear of personnel areas and any hazard of ignition on the vessel.
It should be noted that a closed tank loading system is re-quired during loading or transfer operation- on the vessel.
This system can be either an automatic or manual closed ullage system or a simple glass visor having an internal wiper device fitted in eaoh ullage opening. The spill overflow system of the present invention may also be used ., .
for bunker tanks, chemic,al tanks, etc., to prevent over-flow loss and hazard in the same manner as with cargo compartments.
In the foregoing specification, the invention has been described with reference to specific exemplary embodiments thereof. It will, however, be evident that various modifications and changes may be made thereunto without departing from the broader spirit and scope of the invention as set forth in the appended claims.~ The speci-fication and drawings are, aocordingly, to~be~regarded ln ;~ ~ an illustrative`rather than in a~restrictive sense.
,` . ~
'. :
~ : ' `
r -': ' .
' '~ ! , : `
:' . ' " ' ; ' ''' ', ' ' ' ' ' ' . ' ' ~ ~
' ' . '.
' " .
.. . ' ': . .` '
Claims (10)
1. In a tanker vessel for the transportation of fluid chemical and petroleum products in water, which vessel includes a hull comprising a bottom and sides, a top deck, a plurality of watertight cargo compartments disposed within the hull between the top deck and the hull bottom for receiving the fluid chemical and petroleum products, and means coupled to said cargo compartments for filling said compartments with said fluid chemical and petroleum products, the improvement comprising, longitudinally disposed trunk line means, branch line means coupled at one end to said trunk line means and at the other end to said cargo compartments, valve means, coupled to said branch line means intermediate the ends thereof, for permitting the free flow of fluid chemical and petroleum products from said cargo compartments to said trunk line means through said branch line means, said branch line means being di-mensioned so as to prevent overpressurization of said cargo compartments during the flow of said fluid chemical and petroleum products from said compartments to said trunk line means, retention tank means disposed in said ves-sel and coupled to said trunk line means for receiving fluid chemical and petroleum products from said trunk line means, whereby fluid chemical and petroleum products overflowing from said cargo compartments during filling thereof are directed from said cargo compartments through said branch line means and said trunk line means to said retention tank means thereby preventing the spillage of said fluid chemical and petroleum products externally of said cargo compartments.
2. The improvement recited in claim 1, fur-ther comprising vent means for said cargo compartments including bypass line means coupled to said branch line means intermediate the ends thereof and in parallel rela-tionship therewith, and pressure/vacuum relief valve means, coupled to said bypass line means intermediate the ends thereof.
3. The improvement recited in claim 2, wherein said pressure/vacuum relief valve means comprised a closed type pressure/vacuum relief valve.
4. The improvement recited in claim 1, fur-ther comprising vent means coupled to said retention tank means for venting gases from said retention tank means to the atmosphere.
5. The improvement recited in claim 1, wherein said valve means comprises a positive type closure valve.
6. The improvement recited in claim 1, wherein said valve means comprises a non-return clapper valve.
7. The improvement recited in claim 1, fur-ther comprising liquid overflow pipe means disposed within said retention tank means, said trunk line means having an end thereof extending downwardly and opening into said retention tank means, said pipe means having an enlarged opening at one end disposed below said end of said trunk line means in said retention tank means for receiving fluid chemical and petroleum products from said trunk line means, said pipe means directing said fluid chemical and petroleum products within said retention tank means, said enlarged opening of said pipe means being spaced apart from said end of said trunk line means in said retention tank means for directly vent-ing gases from said trunk line means into said retention tank means.
8. The improvement recited in claim 1, fur-ther comprising line flow alarm means, coupled to said trunk line means, for indicating the flow of fluid chemi-cal and petroleum products in said trunk line means.
9. The improvement recited in claim 1, wherein said retention tank means is located adjacent a side of said hull of said vessel.
10. The improvement recited in claim 1, wherein said retention tank means comprises a plurality of interconnected empty cargo compartments of said tanker vessel.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000375534A CA1136495A (en) | 1981-04-15 | 1981-04-15 | Spill overflow prevention system for tanker vessels |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000375534A CA1136495A (en) | 1981-04-15 | 1981-04-15 | Spill overflow prevention system for tanker vessels |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1136495A true CA1136495A (en) | 1982-11-30 |
Family
ID=4119747
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000375534A Expired CA1136495A (en) | 1981-04-15 | 1981-04-15 | Spill overflow prevention system for tanker vessels |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1136495A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112960067A (en) * | 2021-01-29 | 2021-06-15 | 广船国际有限公司 | Ship section stowage method |
-
1981
- 1981-04-15 CA CA000375534A patent/CA1136495A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112960067A (en) * | 2021-01-29 | 2021-06-15 | 广船国际有限公司 | Ship section stowage method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4292909A (en) | Spill overflow prevention system for tanker vessels | |
| JPS58196395A (en) | Storage tank | |
| NO133461B (en) | ||
| KR20210142103A (en) | A fuel tank arrangement on a ship and a method of relieving hydrogen from a liquid hydrogen fuel tank arrangement | |
| US4233922A (en) | Fluid transfer system for tanker vessels | |
| KR20190060559A (en) | Lng bunkering station module and lng fueled ship having the same | |
| US4144829A (en) | Method and apparatus for venting hydrocarbon gases from the cargo compartments of a tanker vessel | |
| US3868921A (en) | Normally vented liquid-storage tank for ships, with closure device for automatically preventing leaking if the ship should sink | |
| US6929039B2 (en) | Marine vessel fuel overflow tank system | |
| US2928436A (en) | Vapor sealed liquid carriers | |
| CA1136495A (en) | Spill overflow prevention system for tanker vessels | |
| US5042582A (en) | Horizontal heater/treater and/or vapor tight oil battery | |
| NO164825B (en) | BALLAST WATER MANAGEMENT DEVICE. | |
| EP0063191A1 (en) | Spill overflow prevention system for tanker vessels | |
| US5222517A (en) | Fluid containment vessel with one or more recessed wells | |
| US3059804A (en) | Safety device for insulated tank | |
| US5901656A (en) | Watercraft with stacked wing ballast tanks | |
| CA1098413A (en) | Combination pressure-vacuum relief and antipollution valve | |
| US1689352A (en) | System for gathering gas from oil tanks, etc., of refineries | |
| IE50874B1 (en) | Spill overflow prevention system for tanker vessels | |
| KR850000139Y1 (en) | Spill overflow prevention system for tanker vessels | |
| US5575340A (en) | Method for extinguishing ship container fires | |
| AU2017442251B2 (en) | Installed fire extinguishing apparatus, especially for the fire protection of use locations comprising endangered structures separated from each other by spaces | |
| KR20090065009A (en) | Vessel attached trap for oil collection | |
| CN109954240A (en) | One kind anti-disappear integrated oil tank safety equipment and method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |