Tanker is a large-scale transportation equipment for transporting oil at sea. After long-term use, a large amount of crude oil dirt and sediment will be deposited in the oil tank, which is very viscous and even in the state of slurry residue. Under the condition of iron as catalyst, heavy oil molecules will polymerize, coagulate and solidify. Oxygen in the air will also promote the formation of oil residue. These paints are fixed on the bottom or wall of the oil tank and are difficult to remove. Manual cleaning of oil residue is not only labor-intensive, but also dangerous, so special machinery is usually used to clean it with detergent. Generally speaking, a special tank washer is installed on an oil tanker. With the cooperation of the heating device, the tank washer heats the seawater containing detergent into high-pressure hot water, and sprays the hot washing liquid with the pressure of 1 ~ 1.2 MPa and the temperature of 90 ~ 100℃ to the oil tank with the capacity of1t. In many cases, the tank washer cleans the oil tank.
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Safety measures for tank washing operation of oil tanker
Number of visits: 1308? Release date: 20 15-06-02
The oil tanker cleaning operation is very risky. How to do well the safety management of cabin washing operation and successfully complete the cabin washing work?
Confirm the types of gas in the oil tank before tank washing, determine the detailed and reasonable tank washing scheme, and make full preparations for tank washing.
1. The personnel involved in tank washing shall be qualified personnel who have been trained in tank washing, and the requirements and emergency measures for tank washing operation shall be specified.
2. Post a crude oil tank washing notice at the tanker tank washing workplace.
3. Before cleaning the fuel tank, thoroughly clean the fuel tank, clean the pipeline and discharge the residual oil.
4. When cleaning the crude oil tank, in order to avoid static electricity, it is necessary to take out the crude oil from the tank with the depth of 1m, which is the same as the oil contained in the tank, with less water and impurities.
5. Confirm:
(1) The tank washing pipeline system has no leakage and is isolated from the engine room;
(2) Various instruments and cabin sweeping systems are normal;
(3) The pressure and oxygen content of the mixed gas in the cabin meet the requirements, and the relevant valves are in the correct position.
6. Do a good job of fire and explosion prevention when washing the cabin. Control ignition source components to prevent combustion and explosion. Such as the construction site shall not appear open flame, electric spark, static electricity, etc.
7. Pay attention to control the gas in the cabin when washing the cabin.
8. When the tank washing water cannot be discharged smoothly, the tank washing machine should be stopped and the tank washing work should be resumed after the tank washing water is discharged.
9. When using heating pipes, ensure that the pipes are intact.
10. When the oil tanker washes the tank, if personnel need to disembark for inspection, they must wear breathing apparatus before entering the tank. And there is a special person on duty in the inspection well.
1 1. When personnel need to disembark after tank washing, they should keep the oil tank ventilated and confirm that the oil tank has been degassed before entering the tank.
12, tank washing tank water treatment method:
(1) discharge at sea as required;
(2) A receiving ship is dispatched from the shore to receive the cabin washing sewage and send it to the shore for treatment.
In order to ensure the safety of tanker cleaning, the tank cleaning personnel should abide by the safety regulations of tanker operation and seriously implement the tank cleaning plan.
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Relevant standards:
JT 154-94 Safety Technical Requirements for Tank Washing Operation
Traffic industry standard of the People's Republic of China
Safety technical requirements for tank washing operation of oil tanker
1 Subject content and scope of application
This standard specifies the safety technical requirements for tank washing operations of oil tankers.
This standard is applicable to oil tankers of 150 gross tonnage and above.
2 terminology
2. 1 cabin washer
It refers to the cabin washing equipment that the nozzle can continuously change the injection angle in the vertical direction with the horizontal rotation of the machine body driven by the driving device. have
Single nozzle cabin washer and double nozzle cabin washer.
2.2 tank cleaning
It refers to the operation of spraying crude oil and water into the cabin through the cabin washing machine to clean the inner surface of cargo oil cabin and its components.
2.3 crude oil cleaning
Refers to the tanker transporting crude oil, which uses the oil it carries as the cleaning medium and is sprayed into the cargo oil tank under high pressure through the tank washer, relying on crude oil.
Its own dissolution will clean up the oil pollution attached to the bulkhead, parts and bilge, and discharge it to the shore together with cargo oil.
2.4 Water washing of water washing tank
It means that water is sprayed into the tank by the tank washer to clean the oil tank. Include that cleaning of product oil tanker and crude oil tankers.
And water washing after tank washing of crude oil.
2.5 Inert gas system
A system for charging inert gas into cargo oil tanks comprises a washing tower, a blower, a deck water seal, a control valve and an oxygen analyzer.
System.
2.6 degassing gas removal
It refers to introducing fresh air into the engine room to remove flammable and toxic gases, so that the gas state in the engine room meets the requirements of safety standards.
2.7 Purging of gas replacement
It means that inert gas is filled into the cabin before the degassing is finished, so that the hydrocarbon gas content is reduced to an excessively dilute state.
3 crude oil tank washing
3. 1 Implement the declaration procedure for crude oil tank washing.
3. 1. 1 Before crude oil tank washing, the captain shall report to the harbour superintendency administration at the port of discharge in time as required by the harbour superintendency administration.
3. 1.2 declaration contents;
A. Number, validity period and place of issuance of the ship's safety structure, safety equipment and international anti-pollution certificate;
B name, position, tanker work and crude oil cleaning experience of the operator;
C. crude oil tank washing plan;
D. other contents required by the port.
3. 1.3 Upon arrival in Hong Kong, immediately report the safety inspection results and the operation plan for oil unloading and crude oil tank washing to the harbour superintendency administration in writing, and obtain the consent.
Unloading and crude oil tank washing can be carried out.
3.2 Provisions for crude oil tank washing operators
3.2. 1 The general person in charge of crude oil tank washing shall be the first mate or captain who holds the Qualification Certificate of Crude Oil Tank Washing issued by the harbour superintendency administration.
Ren.
3.2.2 If the ship does not have a crew meeting the requirements of Article 3.2. 1 or a new ship, the company shall send a supervisor and inform the situation of "crude oil tank washing".
The certificate supervisor shall go to the ship to guide and supervise the crude oil tank washing operation.
3.2.3 The main personnel involved in the operation shall have at least 6 months' oil tanker working experience, and have engaged in oil unloading and oil unloading during their work on board.
Crude oil tank washing operation, or received professional training in crude oil tank washing, familiar with the contents of crude oil tank washing operation and equipment manual.
3.3 Provisions on crude oil tank washing equipment
3.3. 1 inert gas system
3.3. 1. 1 Inert gas system must have two fans, the total capacity of which should be 1.25 times of the total capacity of cargo oil pump.
3.3. 1.2 The fixed oxygen analyzer must be calibrated before each use.
3.3. 1.3 The sealing fluid of the pressure/vacuum relief valve must be non-freezing fluid or high-grade lubricating oil, and its filling amount ensures the high-pressure relief pressure.
The positive pressure and negative pressure release pressure of the breathing valve are equal to the negative pressure of the breathing valve.
3.3. 1.4 When the inert gas system stops using, water must be continuously supplied to the deck water seal to keep the water level of the water seal normal and make it effective.
The height of water-sealed water column is greater than the positive pressure of breathing valve and pressure/vacuum release valve.
3.3. 1.5 The oxygen content and gas temperature of the inert gas supplied to cargo tanks by the inert gas system shall not exceed 5% (by volume).
60℃。
3.3.2 The cabin washer must be fixedly installed in the cabin, and the top cabin washer should have an adjustment and indication device for the vertical angle and rotation direction of the nozzle.
3.3.3 Crude oil tank washing oil pump, but the special pump can also be cargo oil pump, and its displacement and discharge pressure should meet the working requirements of tank washing machine.
3.3.4 The pipeline system for crude oil tank washing must be fixed and can withstand the pressure of 1.5 times the maximum working oil pressure, and cannot be connected by hoses. it
The pipeline cannot pass through non-dangerous areas such as engine room, and the pipeline connected with the cabin washing heater must have two stop valves or one stop valve and one stop valve.
When there is a blind plate, the main pipeline should be equipped with a pressure gauge and thermometer.
3.3.5 In the cargo control room, the oil tank level shall be telemetered, and a high level alarm shall be set.
3.3.6 The pressure of the following components shall be telemetered in the cargo control room;
A. Suction and discharge pressures of washing liquid supply pump in crude oil tank;
B. Suction and discharge pressures of cabin cleaning pump and cabin cleaning syringe;
C. pressure in the main pipeline of the inert gas system.
3.3.7 Explosion-proof communication equipment approved by the competent authority must be equipped between the cargo control room, the deck and the cargo oil pump cabin.
3.3.8 At least 2 portable oxygen analyzers shall be equipped.
3.4 crude oil tank washing operation plan
3.4. 1 The crude oil tank washing operation plan shall be formulated at the same time as the unloading plan. The plan shall be prepared in accordance with the Manual of Crude Oil Tank Washing Operation and Equipment.
According to the cargo situation of this voyage
Status, port oil unloading rate, scheduled tank washing times and purpose, and submit the "Crude Oil Tank Washing and Unloading Plan" to the captain for approval and signature.
If there is a crude oil tank washing supervisor
On the ship, the plan prepared by the first mate must also be signed and approved by the supervisor.
3.4.2 The crude oil tank washing and unloading plan shall include the following contents:
A. crude oil unloading and ballast procedures before tank washing;
B. trim value required during tank washing of crude oil;
C detailed operating procedures for crude oil tank washing, such as pumps and pipelines used for crude oil tank washing, and liquid level control of oil supply tank and dirty oil tank.
Planned cleaning of oil tank
As well as the cleaning sequence, the cleaning method, the setting of the cleaning range of the vertical angle of the nozzle, the cleaning cycle or the horizontal rotation speed of the nozzle.
Budget of shear stress and bending moment during unloading/cleaning.
3.4.3 Drivers and pump operators should master the contents of crude oil tank washing and unloading plans and implement them as planned.
3.5 Carry out crude oil tank washing operation.
3.5. 1 crude oil tank washing operation can only be carried out after approval at the unloading port.
3.5.2 During the crude oil tank washing operation, warning signs shall be posted or hung on the main passages and bulletin boards.
3.5.3 The cabin washing operation must be carried out from sunrise to sunset:
3.5.4 The tank washing oil must be of the same variety as the oil in the tank to be cleaned, and impurities and water shall not be mixed in the tank washing oil, so it should be reserved.
The oil tank used as tank washing oil can only be used for tank washing after the tank depth of 1m is removed.
3.5.5 When the dirty oil tank is used as an oil supply tank for tank washing, all crude oil mixed with dirty oil must be unloaded first, and then cleaned with crude oil before loading.
Add clean cargo oil as cleaning.
Use crude oil. The crude oil pumped back from tank sweeping cannot be directly discharged into the tank, but should be discharged into another dirty oil tank first, and precipitated and separated at a fixed time.
And flows into it through a horizontal communication pipe.
Cabin.
3.5.6 In case of any of the following circumstances, immediately notify the responsible person in Hong Kong:
A. when the crude oil tank washing plan changes;
B. When the equipment related to crude oil tank washing fails;
C. When the unloading speed or onshore pipeline system changes;
D. in case of other emergencies.
3.6 Safety measures for crude oil tank washing operation
3.6. 1 safety inspection
3.6. 1. 1 Before the ship arrives at the unloading port, it shall be inspected according to the items in the Safety Confirmation Form for Crude Oil Washing (Appendix A, Table A 1).
3.6. 1.2 Before the crude oil tank washing operation starts, the tank washing operation can only be started after all the inspections in Table A2 in Appendix A are confirmed.
3.6. 1.3 During crude oil tank washing, check according to Appendix A, Table A3, and stop tank washing if there are unqualified items.
3.6. 1.4 After the crude oil tank washing operation is finished, check it according to Appendix A, Table A4, and report to Hong Kong that the crude oil tank washing operation is finished safely.
3.6.2 Control of oxygen concentration.
3.6.2. 1 Before washing the tank, the oxygen concentration in the tank shall be measured at 1m below the deck and in the middle of the tank space.
During tank washing, the oxygen concentration of 3.6.2.2 crude oil must be lower than 8%. The oxygen content of the inert gas main pipe cannot exceed 5%, because the tank
Furnace combustion fluctuation and other reasons.
When the oxygen content rises instantaneously, it cannot exceed 8%.
3.6.3 Pressure control in oil tank
During the crude oil tank washing operation, the air pressure in the cargo tank should be kept at positive pressure.
3.6.4 In any of the following circumstances, the crude oil tank washing operation must be suspended:
A. When the oxygen concentration in the cabin exceeds 8%;
B. When the inert gas system fails;
C when the cabin pressure drops below 1000Pa;
D. When the crude oil tank washing pipeline system leaks oil;
E. When the crude oil tank washing pump fails;
F. When the crude oil tank washing pressure gauge fails;
G. When the control function of the cargo control room fails;
H. in case of other emergencies.
3.6.5 If the crude oil tank washing operation is suspended for any reason mentioned in Article 3.6.4, it must be confirmed when to resume the crude oil tank washing operation.
The reason for the pause has been eliminated.
Resume crude oil tank washing operation.
4 water washing box
4. 1 Equipment requirements for water washing tank
4. 1. 1 fixed cabin washer should seek common ground in article 3.3.2.
4. 1.2 when the mobile cabin washer is put into the cabin, it must be firmly hung on the deck with anti-static rope, and the connecting hose must not leak oil and be kept in good condition.
Grounding.
4.2 Plan of Water Washing Tank
4.2. 1 Before the cabin washing operation, the first mate shall formulate the purpose of cabin washing according to the ship's equipment. Such as repairing ships or other engine room activities or changing oil.
According to the specific requirements of tank washing, make a tank washing plan and submit it to the captain for approval and signature before implementation.
4.2.2 The water washing tank plan shall include the following contents: landscape of pipeline system, requirements of regulating valves, requirements of pumps and control of dirty oil tanks.
Scheduled oil tank and tank washing sequence, tank washing method, position and height setting of tank washing machine, tank washing time and tank air during tank washing.
Physical condition and safety precautions.
4.3 Implement water washing cabin operation.
4.3. 1 After crude oil washing, all cargo oil tanks should be washed with crude oil first, and then washed with water. The implementation steps and technical requirements are as follows.
Implement the crude oil tank washing plan.
4.3.2 Clean the water tank with a portable water tank cleaner. All hoses should be connected before the cabin washer is hoisted into the fuel tank, but not before the cabin washer is hoisted out of the fuel tank.
You can disconnect any connection so that
It must be strictly implemented in accordance with the relevant provisions of Article 4.4 "Safety Measures for Water Washing Cabin Operation".
4.3.3 Open tank washing shall be adopted as far as possible, and oily sewage after tank washing shall be discharged into cargo oil tanks with sufficient tank capacity.
4.3.4 If circulating tank washing is adopted and two sewage tanks are used, the tank washing sewage is pumped into the primary sewage tank and separated by precipitation.
After that, the clear water in the lower part flows into the secondary sewage tank through the communication pipe, and after a certain period of precipitation and separation, the clear water is pumped from the lower part by the liquid supply pump for further supply.
Used for cabin washing.
4.4 Safety measures for water washing cabin operation
4.4. 1 Safety measures for washing non-inerted oil tanks
4.4. 1. 1 One cabin cannot use four cabin washing machines with flow less than 35m3/h at the same time. If the flow rate is 35~60m3/h,
No more than three cabin attendants.
Taiwan Province.
4.4. 1.2 Before putting the mobile can washer into the oil tank, all hose joints must be connected and the grounding should be tested for good and continuous.
Before the tank washer is taken out of the oil tank, it is not allowed to remove any connectors and grounding wires.
4.4. 1.3 circulating water is not allowed to flush the water tank.
4.4. 1.4 Chemical additives are not allowed.
4.4. 1.5 The heating temperature of tank washing water shall not exceed 60℃, and the heating temperature of tank washing water for Class III oil cargo shall not exceed 80℃.
4.4. 1.6 The operation of measuring or lifting other instruments must be carried out through the set measuring holes. Otherwise, it will be allowed to enter after 5 hours of cabin washing.
Do this kind of homework.
4.4.2 Safety measures for flushing tank of inerting oil tank
4.4.2. 1 Before the cabin washing operation, the oxygen concentration in the cabin must be measured with a portable oxygen detector, and its value must be below 8%.
During the tank washing operation in 4.4.2.2, if the oxygen concentration in the oil tank is greater than 8% or the inert gas system fails, the tank washing operation must be suspended.
Until the conditions are met.
The cabin washing operation can be resumed.
When washing the cabin in 4.4.2.3, positive pressure should be maintained in the cabin to prevent air intrusion. If there is negative pressure, the cabin washing operation should be suspended.
4.4.3 Safety standard for mobile cabin washer and its connecting hose.
4.4.3. 1 The shell material of the mobile tank washer shall meet the requirement that it will not generate sparks when contacting with the internal structure of the oil tank.
When connecting hoses, 4.4.3.3 shall ensure effective electrical connection between cabin washer, hose and fixed water supply system.
When the 4.4.3.4 cabin washer extends into the cabin, it should be hung with anti-static rope, and the hose should not be stressed.
5 degassing operation
Preparation before degassing
5. 1. 1 Before degassing operation, the first mate shall make a degassing operation plan, and submit it to the captain for approval and signature before implementation. The plan should
Including the way and time of ventilation and degassing, the equipment used and the degassing standard reached.
5. 1.2 Prepare the ventilation and degassing equipment and confirm that it is in a safe and available state. Only hydraulic, pneumatic or steam driven movements are allowed.
Fan or blower type.
5. 1.3 notify the crew and nearby ships or ports, etc. , and comply with all relevant safety matters.
5. 1.4 The cabin air conditioner adopts internal circulation mode.
5.2 degassing operation
5.2. 1 degassing procedure of inert gas system 5.2. 1. 1 First, drive gas with inert gas until the hydrocarbon gas content in the cabin is reduced to 2% by volume.
Degassing operation can only be started under the following conditions. During gas replacement, inert gas should be sent to the oil tank at a low speed to prevent unfavorable gas agitation.
5.2. 1.2 Use an instrument that can measure the percentage concentration of hydrocarbon gas in anoxic environment (common explosion detectors are not suitable for this situation) to measure the cabin.
Internal hydrocarbon gas concentration, confirm its value is lower than 2%.
5.2. 1.3 Before degassing begins, the tanker shall be isolated from other oil tanks. When using a mobile fan or blower to send air into the oil tank, it should be
Use a canvas hammer to connect one side of the hammer to a fan or blower and extend it to a distance of 1m from the bilge. The fan or blower shall be installed in the hatch.
On the farthest diagonal. Open the hatch cover and close the inert gas inlet.
5.2. 1.4 Dilution method can also be used for degassing, that is, the fan of the inert gas system directly sends air into the cabin through the inert gas pipeline for degassing.
Gas operation. However, the inert gas fan should be adjusted to the maximum capacity so that the gas in the oil tank can produce the maximum deflection. And should be returned to the inert gas source.
Close the pipeline of the inert oil tank and the inert gas inlet.
5.2.2 Degassing procedure of inert gas-free system
5.2.2. 1 Install a movable fan or blower on the cabin washing hole at the diagonal of the hatch, and connect the canvas air duct with the lower end of the air duct.
Into the cabin, from the bottom1m.
Location. Open the hatch cover.
5.2.2.2, all openings should be closed before individual oil tanks are formally ventilated.
When the public ventilation system is used for all oil tanks in 5.2.2.3, each oil tank should be completely isolated to prevent collusion between oil and gas.
When a mobile fan or blower is used in 5.2.2.4, it should be properly connected to the deck, so that the conductivity between the fan and the deck is good.
5.2.2.5 fixed degassing equipment can be used to degas more than one oil tank at the same time, but when cleaning one oil tank,
Industry, this degassing equipment is not allowed to be used.
After degassing the oil tank in 5.2.2.6, it takes 10 minutes for gas detection to make the gas relatively stable and metered.
At different heights.
Go on. If it still does not meet the standard after the test, it should continue to be ventilated and degassed.
After degassing operation in 5.2.2.7, the ventilation system, especially the pressure/vacuum valve (P/V valve) and high pressure should be carefully checked.
The integrity of quick exhaust valve. At the same time, check and clean the valve or ventilation standpipe with flame protection cover.
5.3 If necessary, other cabins, such as special ballast tanks (SBT) and dry cabins, shall be degassed by safe and effective methods.
Go on.
Appendix a
Safety confirmation form for crude oil tank washing operation
(Supplement)
Table A 1 Safety Confirmation Form for Crude Oil Tank Washing (before arrival in Hong Kong)
Ship and shore records, used for serial number verification and confirmation.
1 Has it been declared to the harbour superintendency administration at the port of discharge?
Has the unloading and crude oil tank washing plan been formulated?
Has the tank washing pipeline been tested with crude oil with the pressure of 1. 1 times the working pressure? Is there any oil leakage?
4 Is the inert gas system working normally? Has its alarm device been tested?
Is the cabin flushing pipeline isolated from the engine room? Is the water heater on the pipeline blocked by a blind plate?
Does the emergency stop device of crude oil tank washing pump work normally?
Are all kinds of instruments used for crude oil tank washing working normally?
8 Does the fuel tank oil level indicator work normally? Has the alarm device been tested?
9 Is the contact device working normally?
Has the 10 oxygen detector been checked and calibrated? Is it working properly?
Table A2 Safety Confirmation Table for Crude Oil Tank Washing (before crude oil tank washing begins)
Ship and shore records, used for serial number verification and confirmation.
1 Is it approved by the harbour superintendency administration at the port of discharge?
2. Has the ship and shore negotiated the cabin washing operation?
Does the qualified operator have experience in crude oil tank washing? If not, is there a crude oil tank washing supervisor?
Did the relevant operators know the implementation of crude oil tank washing in detail? Do you have the ability to work?
Is the sign of crude oil tank washing hung up?
6 Is the oxygen concentration in the fuel tank lower than 8%?
7 is the pressure in the oil tank higher than l000Pa?
Is the cabin washer ready?
9 Is the valve leading to the cabin washer open?
10 has the float level gauge been put away?
Table A3 Safety Confirmation Table for Crude Oil Tank Washing Operation (During Crude Oil Tank Washing Operation)
Ship and shore records, used for serial number verification and confirmation.
1 Are there enough crude oil tank washers?
2 Is there oil leakage in the tank washing pipeline system?
Is the cabin washer working properly?
4 Is the pressure in the tank washing pipeline normal?
5 Is the oxygen concentration in the fuel tank lower than 8%?
6 Is the pressure in the oil tank higher than 1000Pa?
7 Is the equipment related to crude oil tank washing working normally?
8 Is the control function of the cargo hold control room normal?
Is there always someone on duty on deck?
Table A4 Safety Confirmation Table for Crude Oil Tank Washing Operation (After Crude Oil Tank Washing)
Ship and shore records, used for serial number verification and confirmation.
1 Are the odor valves of the oil unloading system and tank washing pipeline all closed?
Has the residual oil in the tank washing pipeline been drained clean?
Are all the valves on the cabin washer closed?
Is the water level of deck 4 water seal normal?
additional information
This standard is proposed by the Ministry of Communications.
This standard is centralized by the Safety Supervision Bureau of the Ministry of Communications.
This standard is drafted by Dalian Maritime University, Dalian Ocean Shipping Company and Dalian Maritime Bureau.
The main drafters of this standard are Ren Dejun, Yin Peihai, Jiang Yong, Bao.
Label: JT 154-94 JT Tank Car Safety Technical Requirements Operation