200

Butane

Propane

Cargo compressor , Deep well pump , Booster pump , Heater , Evoporizer , IG plant or N2 plant

Via water spray

Cargo compressor need for increase temperature can be during loading to avoid vacuum , after discharging to remove cargo residue , gas coming from vapor line to compressor and return to hold as hot gas can be until abt 60 degree .

Tank Abt 17 bars (USCG 14 bar ),For construction of tank used allow steel , INVAR steel (Carbon not capability propane under 0°C) , Aluminum not capability with Butane ) can be allow with stainless steel ,dwt 1,000-12,000 m3 ,Temp 0/+45/Can be-10/+55 , Tank Independed C Secondary barrier Not compulsory , Cargo pump DeepwelI, Colling type water spray , IG plant or N2 nitrogen , Booster, Heater, Cargo LPG and ammonia , Cargo compressor without condenser or economizer . On board cargo colling via water spraying on cargo tank , Cargo compressor need for increase temperature can be during loading to avoid vacuum , after discharging to remove cargo residue , gas coming from vapor line to compressor and return to hold as hot gas can be until abt 60 degree . Possible collect cargo residue if present deck tank cargo hold be have more pressure than storage tank . In hold space dry air dew point not less -20° .

Semi refrigerator – Tank Abt 4-7 bars (USA 4 bar), dwt 3,000-20,000 m3,Temp -48 /-104 , Tank Independed C Secondary barrier Not compulsory, cargo hold constructed with allow carbon steel – aluminum , nickel 2% for tank -48° and nickel with 9-12° for carriage ethane - 104°, Colling Compressor 2 stage Can be 3 stage R22, Cargo pump DeepwelI ,IG plant can be PSA Nitrogen, Booster, Heater, Evoporazier , Cargo LPG , ammonia , VCM , Propylene , Butadiene , Ethelene (-104) , cargo tanks insulation polyurethan foam .

from tank Vapour to liquied separator , From liquied separator to first stage , From first stage to economizer, via Economizer to 2nd stage, from 2nd stage to condenser , from condenser via Thermo-expansion valve to tank

Fully Refrigerator - Tank Abt 0.7 bars (USA 0.4 bar) normally working pressure 0.35 USA 0.25 bars, dwt 20,000-85,000 m3,Temp -48 , Type C or Tank Independed A Secondary barrier compulsory (Primary Material stainless steel or steel with allow materials 9% nickel – Secondary barrier Liquid tight thermal insulation Based on polyurethane foam panel -Intrbarrier space (Space should be fitted inert gas) – Cargo tank support, As per IGC code secondary barrier able to contain tank leaking 15 days, Colling Compressor 2 stage Can be 3 stage R22, IG plant can be PSA Nitrogen, constructed with allow carbon steel – aluminum , nickel 2% for tank -48° ,usually constructed for carriage type of cargo , Submersible Cargo pump , Booster, Heater, Evoporazier , Cargo LPG , ammonia , VCM , Propylene , Butadiene .

Cargo Blue , Vapor – Yellow , Purge / condenser - Orange, Condensate – Orange , Nitrogen light Green , Glycol – Brown , Vent/Drain – Red , Fire line – red , Sea water dark green

80

Deck Storage Tanks – When we receive Cargo to deck tank what is under Innert condition will be increasing pressure , By vapor line possible send mix Nitrogen-Cargo vapor to shore return gas line , shore flare or to cargo tank because no any choose in cargo tank on bottom via vapor-liquid crossover, pressure in cargo tank can be come from 0.1 to 1 bar and some surveyor can count this as cargo in tanks. Some gas carriers, notably fully-refrigerated and semi-refrigerated LPG carriers, are fitted with one or more deck tanks. These small Type C tanks are primarily used when changing grades or can be used when discharging. When changing grades, they can be used to collect residual cargo amounts or, if carrying a quantity of compatible cargo, can be used for the purposes of gassing up.Design requirements (relief valve systems) and application limits (use of deck tanks not being permitted for the carriage of certain cargoes) can be found in the IGC Code. Deck tanks are usually listed as cargo tanks on the Certificate of Fitness.

The inhibitor content, ascertained from the Certificate, needs to be maintained at sufficient levels at all times for inhibited cargoes, such as butadiene or VCM, stored in the deck tank. If on board not installed Deck storage tank possible keep cargo in 1 cargo hold commenced cooling and gassing-up abt 2 days before arrival .

Type C, Type B, Tape A, Spherical Moss tank

15

Tank C

Tank A, Partly tank B

Cargo holds type : Type C - Independed , Type B , Type A Primary Barrier - The inner containment system when the cargo containment system comprises of two boundaries Secondary Barrier: The secondary barrier is to act as a temporary containment for any envisaged leakage of liquid cargo from the primary barrier. It is designed to contain any leakage for a period of at least 15 days. Insulation & Interbarrier Space Interbarrier spaces around the cargo tanks are continuously inerted.

The annular space is the space between the cargo tank and the insulation layer. An LNG tank comprises an inner tank containment system within an outer tank layer that, in the event of failure, must be capable of containing the cargo for a minimum of 15 days . N2 continuously flows within this space, and it is analyzed to check for any traces of LNG before it returns to the hold space. This allows the earliest possible detection of any leakage

liquid line, vapour line , Booster , heater vaporizer, deck tank– Can be 2 separated group for example 2 different cargo

Propane , Butane , Propene , Butene , Isobutene

Present in crude iol gases condensate is mix ethane , propane , Butane and heavy hydrocarbons

Ethane, Ethelene

Ammonia

Isoprene

Chlorine

VCM, Butadiene , Propadiene

Propane , Ethane , Methane , Butane

boiling point -42° , Liquid D-0.515 m3 ,Air D- 1.5 kg,

-47° , Liquid D-0.609 m3 ,Air D- 1.91 kg

boiling point -0.5° , Liquid D-0.720 m3 ,Air D- 2.05 kg

boiling point -11°, Liquid D-0.625 m3 ,Air D- 2.59 kg

boiling point -6° , Liquid D-0.620 m3 ,Air D- 2.05 kg

boiling point from -13° D-0.911 m3 ,Air D- 2.15 kg

-4° (1,3) to +10° (2,4) D-0.615 m3 ,Air D- 6.0 kg

don’t have colour , don’t have odour(smell) , don’t have corrosion . Normally to say colourless , odourless and not reacted to corrosion .

have strong odour like ammonia , vcm .

Ammonia NH3 should never be loaded into a tank that contains an atmosphere of combustion-generated inert gas, as the ammonia will react with the carbon dioxide in the inert gas producing carbamates. These are white powdery substances that can cause blockages in lines and pumps and will on tank Bulkheads., 16. Ammonia shipment / requirements / hazards risk ? – Area from superstructure until fwr . Before loading ammonia cargo tanks and line should purge under Ammonia vapours , lower flammable limit LFL 15%- UFL 25% in Europe loading only on nitrogen , First gasinup hold until min 98% Ammonia vapour need supply on top part cargo tank because Ammonia lighten then Air , During loading on Air never not use top spray to avoid accumulate strong static electro hit specially on beginning of loading .

Loading Ethelene – Loading on nitrogen oxygen limitation 0.2-0.5 % , dew point not over -40°C only after this possible commenced gasin up , Before loading cargo hold temperature -70/-80°C , Cooling tank not over -10°C per hrs

Before commenced loading the cargo pipes and cargo tanks should be filling under Innert Gas or Nitrogen or Nominated cargo vapour . Loading LPG Gases possible on only innert gas or nitrogen if dew point +5°C but under load propane can be mixed with innert gas . Important during gasin up use effect piston what is not give possibility to mix cargo vapour and innert gas . Purge propane gasin up going from bottom to top . Loading izo-Butane , butane n1 , n2 , Butene only on nitrogen .

Requirement tranfer in Stainless steel tanks , Loading under positive nitrogen pressure to avoid Air ingress , strictly temperature control , highly flammable cargo . Flammable limit from 2.8% until 37%

That is single bonds (connection) between atoms H – hydrogen and C – Carbon . All of this ig Grope alkane like Methane ,Ethane , Propane , Butane with this Gases possible do every this like heating , cooling , pressing , transferring and formula of molecule is not changes — contain only carbon-carbon single bonds. . During carriage this kind cargo no need add Inhibitor .

That is Groupe Alkene what is have contain carbon-carbon double or triple bonds and risk of polymerization .

is the pressure at which the vapor is in thermodynamic equilibrium with its liquefied gas surface. When temperature of liquefied gas increases - SVP also increases but gas remains liquified.

Partial pressure is a pressure of an individual gas in gas mixture. It is the pressure the gas would produce if contained in a cargo tank separately. Sum of Partial pressure is equal to the total pressure in the tank. No any cargo is not 100% clear Gas Like 100% Butane cargo have 98% Butane and 2 % other gases any way in gas will some MOL(Procentage) of other fraction cargoes for example 4 fraction the gas pressure will summered based on all partial Gases partial pressure .

That is temperature under which cargo already not possible to return to liquefied by pressurization under any pressure .

The dew point is the temperature at which the vapor of a liquid forms the first bubble of liquid dew , commenced the condensation of vapour .

When cargo mixed or mixture is the temperature where the first bubble of vapour is formed when heating a liquid consisting of two or more components .If it a pure liquid ,then the bubble point is called the boiling point .

Difference dew point – Boiling point : The dew point is the temperature at which water vapor in the air condenses into liquid water, while the boiling point is the temperature at which a liquid changes into a gas.

A gas's "melting point" refers to the extremely low temperature at which it transitions from a gaseous state to a solid state, essentially becoming a solid by freezing; since gases are already in a dispersed state, their melting points are very low and require significantly colder temperatures to reach compared to liquids or solids at room temperature.

That is temperature when cargo can be explosive/flammability with open fire source. For example propane -105

That temperature under which cargo gas can auto explosive by self with open fire source for example propane is +450° .

Add hydrocarbon radical to cargo for strong odor(small) . Human should be identify strong odor/small already on LEL 20% .

Ideal gas moleculas do not attract or repel each other and cargo hold bulkheads . The only interaction between ideal gas melocules would be an elastic collision upon impact with each other or elastic collision thus the wallas of container .

Tanker Safety Guide 3rd Edition, Cargo loading manual, IMDG

– Inspection holds → Draining → Inerting →Gassing up → Loading→ Discharging → Max Stripping → Liquid free→ Innerting → Aeration → DD.

Propane and Butane is capability cargo If charterer not required made change grade possible load without procedures of change grade . For gassing up will be required 2-3 times mores load cargo .

1)Dedactible trade , capability trade , change trade - chart possible find in IMDG part 2 or Cargo loading manual on board (As per IGC is compolsure to be have on board ) or Tanker Safety Guide las edition3 , Check Oxygen % , Dew point , Last cargo content , СO2 Carbone dioxide and CO carbon monoxide Special for Polymerize and Ethylene. , 2)Discharging maximum cargo and stripping (If equipped), 3)Purging loading hose line on completed discharging vessel close manifold if purge will be from shore open manifold residue will come to cargo hold if from vessel to shore close tank valve keep close manifold made by compressor exceeding positive pressure open manifold residue from hose coming to terminal storage tank . , 4)Warm up tank – liquid and vapor previous cargo free (Warm up by heaters in cargo hold well or compressor send hot gas to cargo well (Vapor will be after 1st stage compressor with temperature abt 50-70°C (Vapor-Compressor-Hot gas line – Vapor crossover – liquid crossover – Tank cargo well – monitor temperature – when all in vapor condition temperature exceed +5 (IG dew from +5 to -60°) +15(after depressuration will drop 6-7°C) commenced degassation Time for warm up for Fully pressurize abt 4-6 hrs , Semi, full-ref 24-48 hrs ., 5)Degassation Marpol don’t have rules abt degassation only for NLS (Noxious Annex 2 12 miles from shore) like for Isoprene, vapor line – crossover- Manifold – hose- Water Degassation until pressure 0.1 bar if need add wages to hose and control degassation (2-3 hrs), 6)Innerting only under above 0°C if IG or Nitrogen heavy then cargo send to bottom part if lighter send from top (Dilution or substitution/displacement ) if dilution will need 2-3 times change tank if Substitution abt 1.2 volume Calculation for 1 exchange Tank Volume / Capacity (rate per hrs) IG or N2 x Tank construction correction from 1.2 to 1.7 (If cargo heavy then air to manifold if easy to vent mast ) IG/N2 need to send from top/bottom via Distribution or Purge or Hotgas or Vapor .Spray-NO. Important to check dew point because in result water condense can freezing and stopped you Discharging pump impeller (Deepweel/submersible ), 7)Purge IG/Nitrogen all pipes compressor , sample point usually it is 5 hrs , 8)Change compressor Oil if required , 9)Aeration (Gas freeining) if Nitrogen send from bottom if Innert from top (3000-4000m3 per hrs) Use Air compressor from IG/Nitrogen plant need change mode to dry air . , 10)Hold inspection – open tank when temperature will same with outer atmosphere Entry in eclosed space Hold inspection CL ,Risk assessment, Hold inspection in case if necessary remove residue , Issue certificate with photo , 11)Dry Air vent to remove all liquid residue On IG/N2 change for Dry Air dew point will be abt -20°C vent abt 3-6 hrs ., 12)Innerting Hold IG or Nitrogen ( If IG from bottom if N2 from top – Dilution or Displacement(Air cushion) Innerting completed when LEL/LFL until below Level . Before commenced Innerting very Important for Tank / Line / Equipment will be good puge by dry air and should no any WATER RESIDUE . Check Oxygen change scale Oxygen meter on 1%, Check by drager Last cargo residue ppm, Check dew point by Dew point meter . IG/N2 dew point -50°C . , 11)Gassing up from Heavy from bottom . Recommended Displacement-parallel kind purge . If charterer made limitation with Cargo for Gassing choose Cascade.(Calculation Liquid density / Vapor density will know how many 1m3 liquid gassin m3 vapor . Tank volume divide on result gassin m3 vapor . Start compressor possible when concentrate IG/N2 will be not exeed 2% by volume . For avoid bleed from compressor IG/N2 better if have time have 100% gassing up . Usually rate Gassing up 1000-1500 m3 . Shore flare possibility 4000m3. If from shore going gassing-up during port stay by going liquid need to pass via ship cargo evoporizer . Time required Fully pressurize abt 8-10 hrs , fully ref abt 10-20 hrs . Possible calculate if from shore rate based on flare for sample 400 m3 per hrs 3000/400= 7 hrs 30 mins . , 12) Compressor set up setting change if requird to VCM/Butadiene mode 13) Line up cargo pipes system and compressor 14)Colling – From top spay line , reduce temperature not over 5-10°C per hrs.

Time for warm up abt 5 hrs – deggasation abt 2 hrs – innerting abt 24 hrs – purge all lines abt 5 hrs - aeration abt 3 hrs – hold inspection abt 2 hrs – innerting abt 24 hrs – gassing up abt 7 hrs

- At terminals where upon completion of cargo operations, liquid cargo residues on the section of the cargo manifold (from the connection with the shore manifold to the first valve on the ship’s line) are drained into water, the procedure of liquid cargo residue draining shall be carried out as follows: a hose connected to the manifold shall constantly be under water . Therefore , it is advisable to attach any weight to the end of the hose. A constant control of the pressure release shall be maintained to avoid emerging of the hose above the water surface . In case the hose is above the water surface and if the drained cargo is blending poorly in the water, propane/butane cargo vapours will drift over the water along the ship’s hull and may penetrate the accommodation and engine room area through the ventilation system. When draining it is required to maintain positive pressure in the accommodation as well as in the engine room.

IGC - 15.4.1 A filling limit greater than the limit of 98% specified in 15.3 may be permitted under the trim and list conditions specified in 8.2.17. For calculation present formula 98% x Refence Condition density / Loading condition density easy to say (Volume 98% x Reference temperature ) , Calculation Cargo Filling limit : - IGC - 15.4.1 A filling limit greater than the limit of 98% specified in 15.3 may be permitted under the trim and list conditions specified in 8.2.17. Only LNG spheric tank have 99% . Remain 2% need for enough pressure vapor intake for compressor and to be not taken liquid to compressor especially during rolling/pitching. For Type C tanks where there is no temperature control and the pressure of the cargo is dictated by the ambient temperature, then the design vapour pressure should not be less than the gauge vapour pressure of the cargo at a temperature of 45C (MSC/Circ.604 For service in especially hot or cold zones these design temperatures should be increased or reduced, as appropriate, by the Administration." this proof can take the form of a Letter of Compliance issued by the Flag State Administration or a certificate provided by the Classification Society which is acceptable to Administrations.). For ammonia, the design vapour pressures would be not less than, say, 17 bar gauge, for propane not less than 14.5 bar gauge., Calculation Loading Filling for Fully Pressurize : LL = 98% x (R / L ) Reference temperature +49C (corresponding to Saturated Vapour Pressure (SVP) of 16 + 1 = 17 bar for propane) . Density of liquid propane at 49C =452 kg/m3 Loading temperature =-5C Density of liquid propane at -5C =536.4 kg/m3 LL =98 x(452 / 536.4) - The tank can be loaded on 82.6 % . Or For example we load Butane FL = LL 98 x (Pr – Relatie densty +45°C / Loaing density) taken density possible from ASTM 56 or Thermodynamic gases condition table ., Calculation Loading Filling for Semi-Fully ref : LL = 98 x max loading /discharge/ transfer density / max service temperature .

Before arrival in port need request via agent/charterer information from terminal : 1) Cargo grade , quantity for loading and cargo specification 2) Pressure and temperature terminal receiver flange , shore backpressure 3) Size flange and type as ANSI,DIN 4) Availability return vapour/gases pipe and capacity if no need to know what the temperature have shore storage if is exceeding our MARVS relictified system soul be sarted before loading and loading rate should adjusted on vessel reliquefied system 5) Maximum rate load/unload and limitation 6) Special terminal rules requirement 7)Draft. , Before arrival need to test : 1) ESD 2) fire protection system (sprinkler/dilution/fire line) 3) Fixed and portable gas detectors 4) emergency alarm system 5) Tank filling alarm system 6) MARVS settings 7) System of open/close ballast valve 8) Air conditioner for inner circulation mode with crack openin for positive pressure in superstructure 9) Cargo line and equipment pressure leaking test– all should be recorded in log book . Also need to check 1) Deck lights 2) Ventilation 3) PPE and breathings apparatus at st.b 4) Condition of fire ventilation protection mesh 5) Familiarized crew with cargo MSDS 6) Instruction crew abt cargo operation . , After completed mooring before cargo operation : 1) Installation Grounding and anti static flange if require 2) Flange terminal connection 3) SSSSCL 4) Check condition of cargo holds and taken cargo samples 5) Secondary check Cargo line and equipment pressure leaking test 6) Check to be completed all necessary check list. , Commenced cargo operation : 1) Small rate for monotonic cooling cargo system and tanks 2) Small rate to avoid hydraulic stress / hydro blow 3) Avoid accumulation static electricity 4) Speed of cooling tank not over 5-10°C 5) All cargo handle valve should be open and during discharging operated only hydraulic or pneumatic valves 6) Smaal reate to avoid cavitation . , During loading – sure need control pressure and temperature especially for activate MARVS PV , during loading for tranfer from 1 tank to another first need fully open next tank and then close loading tank . , Completed loading – Before completed loading need relevant earlier inform terminal abt reduce rate , should be with small rate , During topping cargo need also calculated remain cargo in cargo pipes , Small rate also avoid hydro blow (On practice hydro blow deended of loading rate if rate less the 1000 m3 per hrs hydro blow will be weak ,On completed loading first should be close shore storage valve then ship manifold , During discharging – discharge pump valve shoulb be closed before closed tank o shore side . ,after completed loading terminal purge Stender and hose by innert or nitrogen to cargo tank , or vessel with use compressor made excess pressure (positive pressure) before manifold and open manifold residue purge to shore storage or vessel tank also shore terminal can purge on fire flare . If cargo have low temperature to avoid ship steel damage better to keep water protection . After disconnection hose possible remove grounding .

1)Made measures Liquid ullage (Sounding ) Floating gauges (Can be Echo sounder gauge ) Other part will be Vapor Sounding . 2)Measure Draft and listing via Clinometer (Can be by draft with difference cm between middle sides ) 3)Ullage need corrected on Draft for count Trim, List, Tape or gauge shrinkage , Float(Buancy) gauge correction possible find in Loading manual table correction . 4) Measure pressure by Usually Surveyor use Pressure hydrometer (official name ASTM D 1657 ) If mixed propane – butane will by calculate vapor density Method ASTM D 2598 Formula , Liquid density method COSTALD (Corresponding state of liquid density ) 15/15 ASTM 54 . Or Thermodynamic Table for liquid density for Vapor ASTM 2598. At present moment Propane,Butane,C4 can be Butadiene calculation via ASTM 54 other From Thermodynamic table. 5) Measured Temperature Liquid and Vapor . 6)When all correction sounding/Ullage done we taken from volume (use Interpolation) we do correction on Hold shrinkage factor in result we have liquid volume . 7) You should to have or from terminal table with real density or What is most usually Relative density R.D. 15/15, (R.D. 20/4, R.D. 15/20 usually not use), R.D. 60/60 USA Covert 60/60 to 15/15 possible with use ATM 21 ,you need to USE ASTM 54(Before been ASTM 53 but now not use ) shore table where present converting coefficient . After we have liquid volume in table we taken on temperature factor reduction volume on 15°C multiply and we have corrected liquid volume . 8) Multiply Corrected volume on density 15/15 and we have liquid tons . 9) Calculate Vapor mass Taken (Not corrected liquid volume on shrinkage) Full Tank volume - Not corrected liquid volume we have Not corrected vapor volume . 10) Multiply Not corrected vapor volume on shrinkage hold vapor we have corrected vapor volume . 11)from MSDS taken Molecular mass and use formula for vapor density : 12) multiply Corrected vapor density on corrected vapor volume we have Vapor mt. 13) Liquid mt + Vapor mt we have total cargo .

COSTALD (ASTM D 2598 Formula)

American Society for Testing Material - Institute of Petroleum. Special tables which are used on all tankers and gas carriers for cargo calculation.

ASTM Cargo density where 15 is temperature of ship steel during building and calculated sounding table and 4 degree fresh water because under 4° fresh water have density exactly 1,000 .

Specific gravity or Relative density is the ratio of the density of a substance to the density of a given reference material.Calculation 60/60 in faregate in C abt 15°

Volume reduction factor is used to correct the volume at real temperature relative to the declared density D15/4. Because vessel can be contructed not under 15° can 2° a temperature correction usually first figure 11 or 12 .

Volume liquid factor (Volume density factor) is a coefficient used to convert the gas component of the cargo in the tank into a liquefied state.

Vessel was been constructed and calculated volume sounding table cargo hold steel have temperature abt 15°C we load cargo for example 0°C sure tank will be shrinkage (Change size , compress) . That factor need for correction volume tank . Correction for the observed liquid temperature varies according to the cargo temperature and allows for steel shrinkage of the tank shell at the cargo temperature. Detailed information can be found in the tank calibration tables. Shrinkage also applies to measuring tape.

Float gauges The float gauge is widely used on all gas carriers. It consists of a float attached by a tape to an indicating device that can be arranged for local and remote readout. Float gauges have valves for isolation so that the float can be replaced in a safe atmosphere.The float should, ordinarily, be lifted from the liquid level when not in use. If left down, liquid sloshing while at sea will damage the tape tensioning device. Float gauges cannot normally register a liquid level of less than 10 cm from the tank bottom. , Radar gauges Tank level gauges working on the same principle as radars are now used on many LNG and LPG carriers. Unfortunately, the frequency they use is absorbed by the chemical bonds in 'unsaturated' hydrocarbons, so these instruments may not be suitable For all cargoes.

Serious if Cargo for Gasisng up in Liquid condition use top spray line . Possible use cascade or displacement light from top heavy from bottom .

From MSDS or Tanker safety guide or from charterer info I will taken Density (𝐿𝑖𝑞𝑢𝑖𝑑 609𝑘𝑔/𝑚3) devide on Density (𝑉𝑎𝑝𝑜𝑢𝑟 1,49𝑘𝑔/𝑚3) = 409 m3 Since 1m3 of liquefied Propylene produces 409m3 of vapours: we will order 50m3 of liquefied Propylene (20000m3 / 409 = 48,9m3)

From MSDS or Tanker safety guide or from charterer info I will taken (𝐿𝑖𝑞𝑢𝑖𝑑 580𝑘𝑔/𝑚3) devide on Density 𝑉𝑎𝑝𝑜𝑢𝑟 1,55𝑘𝑔/𝑚3 = 409 m3 we will order 50m3 of liquefied Propane (20000m3 / 374 = 54m3) QUANTITY OF PROPANE COOLANT should be 2-3 times more than in normal cooling (NO BUTANE RESIDUES). For example, if it is necessary to take 54m3 of the Propane coolant – make order for 54m3 x3 = 162m3.

Light Gas from top Heavy Gas from bottom

method based on difference density . First need started with slow rate abt 200-300 m3/hrs to made in tank piston (Air cushion )Nitrogen recommended to be with temperature +50/+70°C Slowly increase rate for keep piston effect for avoid dilution.For check that piston (Air cushion) is working need to check hydrocarbon by tank scope / gas scope. NEVER not use top spray line to avoid turbulence , Use Distribution or Purge or Hotgas line or vapor line , Keep pressure in tank with not over 0.1 bar . If during innering will be stoppages need commenced all again because atmosphere in tank will be similar . Possible do in parallel with few tanks . For change tank need abt 1.3-1.5 tank volume .

send N2 from top first tank , discharge wll be from bottom to top next tank . Innerting should commenced from tank of most of small capacity . For change tank need abt 1.3-1.5 tank volume . This type will taken a little more time the in parallel but more economy for example N2 will be less working and will less use Lubrication Oil for IG or N2 plant what is expensive .

Important difference Light Gas we send bottom Heavy Gas send to top , Send IG /N2 from top/bottom with max high speed temperature +50/+70°C use if possible Spray line, Most of the fast method but will be high consumption IG/Nirogen and Plant Oil . Can from shore from cars/trucks . Pressure keep not above 0.1 bar. Can be return gas to shore line . At port use manifold of vent mast prohibited or open sea or anchorage . Consumption N2 will 2-3 more then Displacement . If from bottom spray line out will be by vapor line .

For example our tank is 3500 m3 – We consider to use displacement metod abt 1.2-1.4 vol change IG rate 200 m3 per hrs : Calculation 3500 / 200 = 17,5 hrs Tank Construction Correction according LGHP from 1.2-1.7 for sample use 1.2 Final calculation time 17.5 * 1.2 = 21 hrs .

For example we have Tank Volume 4000.0 m3 Oxygen in tank 21% need Innerting until 3% . Natural Logarifm ( In ) figure will be 21/3=7 , Proceed to table with Natural logorifm and we have result for example 1,946 change times + 10% total 2,15 . For exxange we have 4000x2.15 = 8600 m3 For example IG/N2 Capacity 500 m3 Total time : 8600/500= 17,2 hrs .

For made Good piston and not be mixed Innerting gas with cargo gas .

During innerting Displacement Air piston.

1

Brand Alfa naval , Kengrim Japan , Result after IGS Oxygen abt 0.5% , Nitrogen 85% , carbon dioxide abt 14% ,Oxide sulphur 10ppm , Oxide Nitrogen 100ppm , Hydrogen 0.1% , carbon monoxide 0.1% Inert gas generator has three main parts: 1) -combustion chamber with scrubbing and cooling (the generator),- 2) refrigerated drier, 3) -adsorption drier.The IGC Code requires continuous oxygen monitoring in the inert gas delivery line and the oxygen content should be no more than 5%. High oxygen content will trigger an alarm, although the generator is not normally shut down on this alarm, the gas instead being diverted to the atmosphere via a vent riser.Inert gas produced by the careful combustion of diesel or gas oil results in a reduced oxygen content. In the inert gas generator the resulting gases are further treated to provide an inert gas of acceptable standard. Apart from plant operation, the final quality of the inert gas depends on the fuel used and, generally, low sulphur content fuel is preferred.

Result after Nitrogen system is oxygen content only abt 4 ppm Nitrogen is abt 95-97% .The membrane separation technology works by passing compressed air over hollow fibremembranes. The membranes divide the air into two streams, one of which is essentially nitrogen plus some trace gases and the other a 'waste' stream comprised of oxygen, water vapor, and carbon dioxide. This system can produce nitrogen or Brand Cirmac PSA system Japan , An alternative method of nitrogen production is called the pressure swing adsorption process. PSA processes rely on the fact that under high pressure, gases tend to be attracted to solid surfaces, or 'adsorbed'. The higher the pressure, the more gas is absorbed. When the pressure is reduced, the gas is released, or desorbed. Air is passed under pressure through a vessel containing a carbon molecular adsorber bed that attracts nitrogen more strongly than it does oxygen . Part or all of the nitrogen will stay in the bed and the gas coming out of the vessel will be enriched in oxygen. When the bed reaches the end of its capacity to adsorb nitrogen it can be regenerated by reducing the pressure, thereby releasing the adsorbed nitrogen. It is then ready for another cycle of producing oxygen enriched air.

Compressor in ER used for ESD system , Control system , Service system , close valves , cargo cooling system , cooling spray system . Air passed from Engine room via air dryer what is do dew point -40° .

– By cargo in condensate condition from top spray line . During cooling condensate will be evaporated and due o this pressure will increase , then need to recompress vapour to condensate condition again . For cooling usually need abt 40m3.

The top of cargo pump column is still warm and bottom has already cooled down due to big difference in temperature. Bottom - Middle - Top of the cargo pump column – just WAIT until middle and top parts of the column cool down, then the shaft will be rotate. Shaft can be stuck up due to ice formation. In this case, methanol injection is to be used (subject to company allowance). As a precaution against cargo pumps becoming blocked with ice, they must be rotated periodically.

The rates at which the cargo tanks can be cooled without creating undue thermal stresses will depend on the design and materials of the containment system. In general cases the recommended cool-down rate shall not exceed 10°C per hour. Reference should always be made to the cargo operating manual to determine the allowable tank cool-down rates.

is the average concentration of a hazardous substance in the air over an 8-hour workday and 40-hour workweek Without protective Breathing equipment .

1000

1000

1000

1000

1000

600

25

20

1