受限空间和氮气危害及防范

Customer Communication Package
受限空间及氮气的危害及防范CSE and N2 Hazards and Prevention May 10th, 2010
Zhou Xingchen
Gasification, Global Solutions Upstream, Shell Projects & Technology
Agenda 内容
1.Incident Sharing 1 ~ 5
事故案例分享
2.Key Learning
主要教训
3.N2 Hazards and Prevention
氮气危害与防范
4.CSE Best Practices
受限空间管理良好实践分享
5.Personnel Gas Detectors
个人气体探测仪
CSE: confined space entry
JHA: job hazards analysis
PTW: permit to work
1.0
Incident Sharing1-5事故案例分享1 ~5
Incident Description事故描述
We were doing site visit at the gasifier. After client HSE staff checked the man hole A5 Shell staff came closer to A5 as well. Suddenly his personnel gas detector vent off and indicated low O2 content. He immediately escaped from the spot.
Site investigation indicated that N2 blowback into gasifier was not shut off before manholes were opened. Steam ejector was started but without opening the steam valve. N2 instead of plant air via the nozzles designed for burn off purpose was still blown into gasifier.
Client was advised to immediately barricade all opened manholes, shut off N2 blowback, disconnect N2 hose and to put ejector into operation.
我们与客户在气化炉进行检查。

当时A5人孔处于敞开状态，客户安全管理人员查看了A5人孔，壳牌员工随后靠近了A5人孔，突然壳牌员工个人气体探测仪发出警报，指示氧含量低，壳牌员工迅速撤离。

现场调查发现，打开气化炉人孔之前，通往气化炉的氮气吹扫未关断，蒸汽抽气器虽然投入，但蒸汽阀门未打开。

气化炉“烧除”程序要求使用工厂风，但接到气化炉烧除通气管线上的是氮气。

当时建议客户立即隔离敞开的人孔，关闭反吹氮气，断开烧除管线上的氮气软管，把蒸汽抽气器真正投入运行。

Incident Classification/RAM Rating –High Potential: P4D Actual: P0
Immediate Causes直接原因:
1.N2 instead of plant air was still blowing into gasifier while manholes were open
气化炉人孔敞开时氮气而非工厂风仍在向气化炉内吹送
2.No safety warning signs erected for opened manholes
敞开的人孔附近没有任何安全警告标识，也未作隔断措施
Underlying Causes间接原因:
1.Operation procedure to start ejector before opening gasifier was not followed correctly
操作程序要求打开气化炉前必须先投入蒸汽抽气器，此程序要求未得到遵守
2.No system isolation plan/blind list was worked out before opening the man holes
打开人孔之前未制定气化炉隔离方案
3.No one checked the system conditions before decision was given to open the man holes
决定打开气化炉之前无人确认系统状态
ck of coordination between operation and maintenance
运行和检修部门缺乏协调
5.PTW system not strictly implemented
作业许可系统未严格执行
6.No adequate system isolation and purging before opening the man holes
打开人孔之前未进行系统隔离、未进行吹扫置换
Lessons Learnt教训:
ck of site management with regard to work planning, risk identification, coordination, supervision and enforcement of clear working
procedures put all site staff at risk –invisible killer of N2 in this case.
工作计划、风险识别、工作协调、监督、强化遵守清晰的作业程序是保证检维修、生产作业安全的重要保证，缺乏对这些环节的管理就会致所有现场人员与风险之中–本案例的风险就是氮气窒息死亡2.It is a good practice to wear personnel gas detectors whenever entering process area no matter the plan is running, shut down or in commissioning.
进入工艺区域，无论装置是在运行、停车还是处于试车阶段，佩戴个人气体探测仪是保证人身安全的可取做法
3.Whenever personnel gas detectors go off immediately escape from the hazardous locations.
Pure nitrogen was blowing from A5 manhole, which was not barricaded Pure nitrogen was blowing from A5 manhole, which was not barricaded A5人孔未隔离，纯氮从A5人孔喷出
A5人孔未隔离，纯氮从A5人孔喷出
Steam valve for J-1601 was not
open while gasifier manholes
were opened
J1601抽气器蒸汽阀门未开，
却打开了气化炉人孔
Fatality Incident Sharing-2
Incident Description
Client was conducting tightness test with N2 in the purification unit in April 2010. One
process engineer checked on site, without wearing personnel gas detectors. He saw one man hole open and went to the man hole to check why. As a consequence he was killed by nitrogen leaking out from the man hole.
2010年4月，净化单元在作氮气气密试验。

一位工艺工程师在现场检查，没有佩戴个人气体探测仪。

他看到有个人孔敞开着，就过去看个究竟。

结果被人孔喷出的氮气窒息而死亡。

Incident Classification/RAM Rating –High Potential: P4D Actual: P4
Fatality Incident Sharing-2
Immediate Causes直接原因:
1.Nitrogen leaking out from the manhole resulted in asphyxiation
从人孔喷出的氮气造成窒息
Underlying Causes间接原因:
1.Poor confined space entry control –the manhole was not barricaded
受限空间管理存在漏洞–人孔未围护
2.Poor awareness of N2 hazards
对氮气危害认识不足
3.No personnel gas detectors worn to warn of exposure to N2
未携带气体探测仪，无法警示已暴露于氮气环境
4.Properly no JHA conducted for the tightness test
气密试验前可能未进行工作风险分析
5.Properly test conditions were not confirmed before the test
气密试验前可能未确认试验条件
Lessons Learnt教训:
1.Do not allow manholes open without barricading and safety warning signs
人孔打开后必须围护，并悬挂/张贴安全警告标识
2.N2 is a silent killer -Never underestimate the N2 hazards
氮气是无声杀手，决不可低估氮气的危害
3.Always wear personnel gas detectors for CSE and working with N2 and gas jobs
进入受限空间或接触氮气或其他有毒、有害、易燃气体，必须佩戴个人气体探测仪4.Conduct and follow proper JHA
开展工作风险分析，并遵守规定的安全措施
Incident Description事故描述
At 8 am on 23rd Feb. 2008 contractor arranged rust removal job inside S1504. Without system isolation, gas testing and application of PTW for the CSE one worker entered the confined space. Around 10:30 am the worker fell to the bottom of S1504 due to asphyxiation. During rescue three fellow workers of him were asphyxiated as well. After plant operators injected air into S1504 the four persons were taken out from the vessel. Three persons died. One was recovered.
2008年2月23日上午8时左右，某安装公司安排对气化装置的飞灰过滤器（S1504）内部进行除锈作业。

在没有对作业设备进行有效隔离、没有对作业容器内氧含量进行分析、没有办理进入受限空间作业许可证的情况下，作业人员进入飞灰过滤器进行作业，约10点30分左右，1名作业人员窒息晕倒坠落作业容器底部，在施救过程中另外3名作业人员相继窒息晕倒在作业容器内。

随后赶来的救援人员在向该飞灰过滤器中注入空气后，将4名受伤人员救出，其中3人经抢救无效死亡，1人经抢救脱离生命危险。

Incident Classification/RAM Rating –High Potential: P5D Actual: P4
Immediate Causes直接原因:
1.N2 ingress into S1504 resulted in asphyxiation
氮气窜入飞灰过滤器中，造成正在进行除锈作业的人员窒息晕倒。

2.Due to blindly rescue the fatality incident was escalated
由于盲目施救，导致伤亡扩大。

Underlying Causes间接原因:
1.Poor safety awareness, poor safety supervision and violation of safety rules by the contractor
施工单位安全意识淡薄，安全管理松弛，严重违章作业。

2.Owner failed to enforce safety rules and to discharge safety management responsibilities
建设单位安全管理制度和安全管理责任不落实。

3.Very poor safety awareness of site individuals
从业人员安全意识淡薄的现象仍然十分严重。

Lessons Learnt教训:
1.Adequate and reliable system isolation is crucial for safe confined space entry.
正确可靠的系统隔离对受限空间作业安全至关重要。

2.Strict CSE control including PTW system must be in place and followed.
必须建立和遵守严格的受限空间管理制度，包括严格的作业许可制度。

3.Always wear personnel gas detectors for CSE.
进入受限空间必须佩戴个人气体探测仪。

4.Enhance safety management for CSE and hot work after utility and feedstock are introduced to plant
引入公用工程和化工物料后，要严格进入受限空间内作业、动火等危险作业的安全管理。

5.Enhance training on risk control and emergency response to improve risk awareness, emergency response and self rescue
加强风险管理和应急知识的培训，提高风险意识和应急自救能力。

Incident Description事故描述
On30 April 2008 during the transfer test with N2, one leakage was found in the manhole gasket of V1104A. Two people were arranged to fix the problem. For unknown reasons the two persons entered the vessel and finally died inside. On 30th April evening their colleagues found the two persons missing but didn’t take any action. On 1st May they found their bodies inside the vessel.
2008年4月30日，V1104A作氮气输送试验，发现其人孔垫片漏气。

安排两个人进行处理。

不知何故，这两个人进入了容器里，最后死在里面。

4月30日夜间，他门的同事发现这两个人没有回来，但没有寻找其下落。

5月1日，在V1104A内发现了二人的尸体。

Incident Classification/RAM Rating –High Potential: P4/5E Actual: P4
Immediate Causes直接原因:
1.N2 inside the vessel killed the two persons
容器内的氮气造成二人窒息死亡
Underlying Causes间接原因:
ck of training -No HSSE knowledge about site hazards and basic safety rules
缺乏培训–对现场危害无认识，不了解基本的安全规定
2.PTW system not followed
作业许可制度未得到遵守
3.HSE Management system not in place/working
安全管理体系未建立/运行
4.No lessons learnt from the Feb. 23 Fatality incident that happened in S-1504 at this site
S1504内曾于当年2月23日发生过氮气窒息3人死亡事件，未吸取教训
Lessons Learnt教训:
1.N2 is a silent killer
氮气是无声杀手
2.Adequate and reliable system isolation is crucial for confined space entry safety.
正确可靠的系统隔离对受限空间作业安全至关重要
3.Strict CSE control including PTW system must be in place and followed.
必须建立和遵守严格的受限空间管理制度，包括严格的作业许可制度
4.Always wear personnel gas detectors for CSE.
进入受限空间必须佩戴个人气体探测仪
ually there should be many barriers (in this case, qualified PTW, isolation plan/blind list, system isolation/tagging &
locking out, JHA/toolbox talk, gas monitoring, safety watch, safety supervision/work supervision, HSE/PTW audit/inspection, HSE induction, contractor HSE management) between hazards and incident. Obviously all these barriers failed.
加强管理，确保安全屏障（高质量的作业票、隔离方案、盲板清单、认真执行系统隔离、挂牌上锁规定、进行工作风险分析、进行现场安全技术交底、气体检测和连续监测、作业安全监护、安全监
2.0
Key Learning 主要教训
Key Learning 主要教训
1.N2 is a silent killer -Never underestimate the N2 hazards
氮气是无声杀手，决不可低估氮气的危害
2.Always wear personnel gas detectors for CSE and working with N2 and gas jobs
进入受限空间或接触氮气或其他有毒、有害、易燃气体，必须佩戴个人气体探测仪
3.Personnel gas detector is the last defense. Continuous gas monitoring inside confined space is proven to be affective mean to ensure CSE safety
气体探测仪是最后一道防线。

使用个人气体探测仪进行连续气体监测，被证明是确保受限空间内人员安全的有效手段4.Gas testing must be up to standard and in professional manner. Gas testing frequency and interval depends on the risk level of the job
气体检测必须规范、专业，检测频率、间隔满足风险控制的要求
5.Whenever personnel gas detectors go off immediately escape from the hazardous locations, without one second delay to check your gas detectors. You can check
your personnel gas detectors later at a safe location.
如果个人气体探测仪报警，要立即撤离有害区域，切勿耽搁时间来查看气体探测仪，要到了安全区域才可以查看气体探测仪。

6.Adequate and reliable system isolation is crucial for safe confined space entry.
正确可靠的系统隔离对受限空间作业安全至关重要。

7.Avoid CSE as much as possible.
尽可能避免进入受限空间，控制无关人员进入受限空间
8.Strict CSE control including PTW system must be in place and followed.
必须建立和遵守严格的受限空间管理制度，包括严格的作业许可制度。

9.Do not allow manholes open without barricading and safety warning signs
受限空间作业完成或暂停时，必须封闭受限空间人孔，或封闭受限空间人孔，悬挂安全警告标识。

10.Enhance safety management for CSE and hot work after utility and feedstock are introduced to plant
引入公用工程和化工物料后，要严格进入受限空间内作业、动火等危险作业的安全管理。

11.Enhance training on risk control and emergency response to improve risk awareness, emergency response and self rescue
加强风险管理和应急知识的培训，提高风险意识和应急自救能力。

12.Ensure to tighten all barriers (qualified PTW, isolation plan/blind list, system isolation/tagging & locking out, JHA/toolbox talk, gas testing and monitoring, safety
watch, safety supervision/work supervision, HSE/PTW audit/inspection, HSE induction, contractor HSE management) between hazards and incidents.
加强管理，确保安全屏障（高质量的作业票、隔离方案、盲板清单、认真执行系统隔离、挂牌上锁规定、进行工作风险分析、进行现场安全技术交底、气体检测和连续监测、作业安全监护、安全监督/工作监督、安全/作业票审查、入场安全培训、加强承包商管理）发挥应有的作用
3.0
N2Hazards and Prevention
氮气危害与防范
N2 –Silent Killer 氮气–无声杀手
Nitrogen properties: invisible, odorless, tasteless, colorless, non-flammable, inert On the living earth: 78 % nitrogen, 21 % oxygen, 1 % argon, trace components
In chemical plant: 99.997 % nitrogen, trace components
氮气特点:无形，无嗅，无味，无色，不可燃、惰性 在地球上：78%氮气，21%氧气，1%氩气，微量组分 在化工厂：氮气纯度99.997%，其余为微量组分
A single breath is death 吸入一口氮气可致命
16
A single breath of pure nitrogen -you will stop breathing instantly breathing is controlled by the CO 2in lungs -not by the oxygen level in ones blood becoming too low. walking into a nitrogen atmosphere, the CO2 in the lungs is depleted (diluted by the nitrogen) and the breathing reflex
suppressed and the brain will stop breathing
Warning:
If no one is there to help you will die in a matter of minutes -basically the time it takes your brain to die or damage because of a lack of oxygen.
ALL oxygen in your blood will be used up and there is no oxygen to replenish your blood.
吸入一口纯氮–就会立即停止呼吸
呼吸是由肺中的CO2“含量高”来控制–而非受血液中“氧含量”低来控制
进入氮气环境，肺中的CO2被氮气稀释，呼吸反射被抑制，大脑停止发送呼吸指令
警告:
如果无人在场施救，受害者将在几分钟内死亡–因缺氧大脑将在数分钟内死亡或受损 血液中的氧气很快消耗殆尽，因呼吸停止，血液无法得到氧气补充。

Good Practices to Prevent N2 incidents 防范氮气事故的良好实践
•
Provide 提供
-Comprehensive HSSE training
全面的安全培训
-
Awareness of nitrogen and CSE hazards
氮气和受限空间危害的知识培训•
Implement 执行
-Warning systems
安全警告体系-Continuous atmospheric monitoring of confined spaces
受限空间连续气体监测
17
-System for safe rescue of workers
事故救援体系
-
PTW system and best practices
作业许可制度和借鉴最佳实践•
Ensure 确保
-Ventilation with fresh air
使用新鲜空气通风
-Uninterrupted flow and integrity of breathing air
空呼供气不间断和可靠性
-
Reliable positive isolation of system before inspection
检查前对系统可靠隔离•
Prevent 防止
-Inadvertent mix-up of nitrogen and breathing air
无意中将氮气与空呼供气混淆
4.0
CSE Best Practices
受限空间管理良好实践分享
CSE Best Practice Sharing受限空间管理最佳实践分享
Confined Space Safety Requirements 受限空间安全管理要求
1.Burn off/depressurize/discharge/purge the confined space
2.Process isolation/tagging &locking out, with confirmed and implemented isolation plan
3.Electrical isolation
4.Radioactive source isolation
5.Safety operator checks for isolation compliance and quality on site
6.Initial gas testing by AGT with BA and confined space attendant
7.Gas environment:O2 =20% ~ 21.5%, CO &H2S =0 ppm, LEL=0%
8.Install temporary gas detectors at strategic locations or levels inside confined space based on risk assessment
9.No risk of dust explosions &falling objects(slag layer) inside confined space 10.Access/scaffolding/ladders qualified
1.对受限空间进行烧除/降压/排放/置换
2.工艺隔离，挂牌上锁，附确认执行完毕的隔离方案
3.电气隔离
4.射源隔离
5.工艺安全员现场确认隔离符合性和质量
6.授权气体探测员首次气体检测使用空呼，并配备监护人员
7.气体测量确保：O2 =20% ~ 21.5%, CO &H2S =0 ppm, LEL=0%
8.根据风险分析，在受限空间内关键部位或标高安装临时气体探测仪
9.确认受限空间内无粉尘爆炸风险及落物（渣）风险
10.确保进出受限空间的通道顺畅，脚手架、梯子符合安全要求11.进入受限空间前取得作业票11.PTW obtained before confined space entry 12.JHA and Toolbox talk
13.Apply ventilation to ensure air quality and temperature inside confined space 14.Provide sufficient lighting of 12V
15.Continuous air monitoring with two gas detectors by workers 16.Maintain radio communication with CCR 17.Rescue plan in place
18.Work party attendant to register and record all entries on tag board 19.Owner standby operator to inspect regularly or monitor continuously 20.Owner maintenance supervisor to supervise the confined space work 21.Confined space attendants to maintain constant communication with entrants 22.Barricade the access to confined space when work suspends 23.Separate fire watcher required for hot work inside confined space 24.Proper PPE including safety harness and torch required
25.Do not operate valves and manholes within confined space isolation boundary 26.No gas bottles shall be brought to inside or close to manholes of confined space 12.进行风险分析，召集班前会
13.进行通风，确保受限空间内的空气质量和适宜温度14.提供足够亮度的12伏安全照明
15.作业人员携带两台气体探测仪进行连续气体监测16.与主控用对讲机保持联系17.应急救援方案到位
18.承包商监护人到位，设置进出登记牌，进出登记，留置胸卡19.业主操作监护人定期检查或连续监护20.业主检维修责任人负责监督
21.监护人与受限空间作业人员保持持续联络
22.受限空间作业暂停时，封闭进入受限空间的通道/人孔23.受限空间动火需要另外设置动火监护人
24.根据受限空间内的风险，穿戴合适的劳保用品，包括安全带和防爆手电
25.不得擅动受限空间隔离边界内的阀门和人孔26.气瓶不能带入受限空间，或置于入口处
Confined Space Attendant Tag Board
5.0
Personnel Gas Detectors 个人气体探测仪
四合一气体四合一气体探测仪
探测仪探测仪，，2020个月保修期个月保修期
4 in1 Personnel Gas Detectors 四合一个人便携气体探测仪。