#209 近接防爆區的起重吊裝作業的緊急應變計畫

 

起重吊裝作業的緊急應變計畫（包括當大氣監測顯示達到 25% LEL 時的設備或工具斷電/關閉措施）

目標：

確保在起重吊裝作業期間所有人員和設備的安全，特別是在大氣監測顯示達到 25% 下限爆炸濃度（LEL）時，能夠迅速採取斷電或關閉設備/工具的應變措施。此計畫概述了如何在需要時關閉設備並疏散現場人員。

1. 作業前準備

• 風險評估：在開始任何起重吊裝作業之前，進行全面的風險評估。識別可能存在可燃氣體或蒸氣釋放的源頭及其可能積聚的區域。
• 大氣監測設備設置：在作業區域內外安裝大氣監測設備，持續監測可燃氣體濃度。確保設備定期校準和測試。
• 通信計畫：建立通信計畫，包括手勢、無線電或其他通信設備，以快速向工人發出緊急情況警報。
• 培訓：所有參與吊裝作業的人員必須接受關於緊急應變計畫的培訓，包括大氣監測設備的使用和緊急關閉程序。

2. 作業期間

• 持續監測：使用LEL探測器持續監測大氣中的可燃氣體濃度。確保LEL讀數對起重機操作員和其他關鍵人員可見。
• 定期通信：保持起重機操作員、地面工作人員和安全官員之間的通信暢通，及時傳達任何重要信息或環境變化。

3. 觸發點：檢測到25% LEL

• 立即行動：

  1. 停止作業：一旦大氣監測顯示可燃氣體濃度達到25% LEL，起重機操作員必須立即停止所有吊裝作業。
  2. 斷電設備：安全地斷電或關閉所有電氣設備、工具及任何可能成為火源的設備。
  3. 通知人員：使用預先確定的信號（如警報、警笛或無線電通信）通知所有人員立即撤離區域。
  4. 疏散：所有人員必須撤離至指定的安全區。撤離過程應有序進行，遵循預定的逃生路線。

• 次級行動：

  1. 隔離區域：在受影響區域周圍建立安全區，防止未經授權的人員進入，直到危險解除。
  2. 通風：如安全可行，啟動通風系統以稀釋氣體積聚，使濃度降至LEL以下。

4. 事故後行動

• 大氣再評估：在考慮恢復作業之前，進行徹底的大氣評估，確保氣體濃度低於LEL的10%。
• 事故報告：記錄事故，包括時間、採取的行動及任何偏離計畫的情況。該報告應在事後總結會議中審查，以識別需要改進的地方。
• 設備檢查：檢查所有設備和工具，確保在關閉過程中未損壞。如有必要，測試並重新校準大氣監測設備。
• 再教育：根據從事故中吸取的教訓，對所有相關人員進行培訓。

5. 作業恢復

• 恢復許可：只有在安全官員或指定負責人確認區域安全後，才能恢復吊裝作業。
• 持續警戒：繼續監測大氣狀況，並強制嚴格遵守緊急應變計畫。

參考資料：

1. OSHA Guidelines：參照美國職業安全與健康管理局（OSHA）有關在潛在爆炸性氣氛中的工作安全指南，特別是針對受限空間和危險大氣的管理規定。
2. NFPA Standards：遵循國家防火協會（NFPA）指南，特別是NFPA 497標準，針對化工處理區域的電氣設備的危險區域分類。
3. API RP 500：參考美國石油協會（API）的推薦做法，適用於石油設施中電氣設備的場所分類，包括Class I, Division 1和Division 2。

此緊急應變計畫旨在確保在潛在危險環境中進行起重吊裝作業時，能夠迅速有效地應對突發情況，保護人員和設備的安全。

Emergency Plan for Crane Lifting Work with Atmospheric Monitoring

Objective:

To ensure the safety of all personnel and equipment during crane lifting operations, especially when atmospheric monitoring detects a 25% Lower Explosive Limit (LEL) being reached. The plan outlines steps to de-energize or shut down equipment/tools and evacuate the area as necessary.

1. Pre-Operation Preparation

• Risk Assessment: Conduct a thorough risk assessment before starting any crane lifting operations. Identify potential sources of combustible gases or vapors and the areas where these might accumulate.
• Atmospheric Monitoring Setup: Install atmospheric monitoring equipment in and around the work area to continuously measure the concentration of combustible gases. Ensure the equipment is calibrated and tested regularly.
• Communication Plan: Establish a communication plan, including hand signals, radios, or other communication devices, to alert workers of emergency situations quickly.
• Training: All personnel involved in the lifting operation must be trained on the emergency plan, including the use of atmospheric monitoring equipment and emergency shutdown procedures.

2. During Operation

• Continuous Monitoring: Continuously monitor the atmosphere for combustible gases using LEL detectors. Ensure that the LEL readings are visible to the crane operator and other key personnel.
• Regular Communication: Maintain open lines of communication between the crane operator, ground crew, and safety officers to relay any important information or changes in conditions.

3. Trigger Point: 25% LEL Detected

• Immediate Actions:

  1. Halt Operations: As soon as the atmospheric monitoring indicates that 25% of the LEL has been reached, the crane operator must immediately halt all lifting operations.
  2. De-Energize Equipment: Safely de-energize or shut down all electrical equipment, tools, and any ignition sources within the vicinity of the detected gas concentration.
  3. Alert Personnel: Notify all personnel in the vicinity using predetermined signals (e.g., alarms, sirens, or radio communication) to evacuate the area promptly.
  4. Evacuation: All personnel must evacuate to a designated safe zone. The evacuation should be orderly and follow the predefined escape routes.

• Secondary Actions:

  1. Isolate the Area: Establish a safety perimeter around the affected area to prevent unauthorized access until the hazard is mitigated.
  2. Ventilation: If safe to do so, activate ventilation systems to disperse the gas accumulation, reducing the concentration below the LEL.

4. Post-Incident Actions

• Atmospheric Re-Evaluation: Conduct a thorough atmospheric evaluation to ensure the gas concentration is below 10% of the LEL before considering the resumption of operations.
• Incident Report: Document the incident, including the time, actions taken, and any deviations from the plan. This report should be reviewed in a debriefing session to identify any areas for improvement.
• Equipment Inspection: Inspect all equipment and tools to ensure no damage occurred during the shutdown. Test and recalibrate atmospheric monitoring equipment if necessary.
• Re-Education: Conduct a refresher training for all involved personnel based on the lessons learned from the incident.

5. Resumption of Work

• Permission to Resume: Only after the area is confirmed safe by a safety officer or designated responsible person, can the lifting operations resume.
• Ongoing Vigilance: Continue to monitor atmospheric conditions and enforce strict adherence to the emergency plan.

References:

1. OSHA Guidelines: Refer to the Occupational Safety and Health Administration (OSHA) standards for working in potentially explosive atmospheres, particularly regarding confined spaces and hazardous atmospheres.
2. NFPA Standards: Follow the National Fire Protection Association (NFPA) guidelines, specifically NFPA 497, for the classification of hazardous locations for electrical installations in chemical process areas.
3. API RP 500: Consult the American Petroleum Institute's recommended practices for the classification of locations for electrical installations at petroleum facilities classified as Class I, Division 1 and Division 2.

This emergency plan is designed to ensure that all crane lifting operations in potentially hazardous environments are conducted safely, with a clear protocol for responding to elevated gas concentrations.