1
Objectives
■ Compare and contrast the types of dry chemical agents used for automatic fire protection systems and the extinguishment
mechanisms involved with each.
■ Discuss the advantages and disadvantages of dry chemical agents for fire protection.
■ Identify the dilemma that could face authorities having jurisdiction when responsible for ensuring that dry chemical systems are capable of functioning as intended.
■ Understand and describe the sequence of operation for a dry chemical system.
■ Discuss the types of dry chemical systems recognized by NFPA 17.
■ Estimate the quantity of dry chemical needed for a total flooding system.
3. 시스템의 개략도
1. Fire detectors sense fire heat in work area.
2. The control panel electrically activates the cylinder control head, which open the cylinder valve and actuates the system.
3. The control panel sounds an alarm, notifies the fire authorities and shuts down airflow in the hazard area.
4. The fire is suppressed as dry chemical is propelled by stored pressure through the discharge pipes and nozzle into the protected area.
we can activate dry chemical fire suppression systems using several different fire detection technologies
• Mechanical fusible links
• Electric thermal detectors
• Flame detectors such as UV detectors and IR detectors
• Linear heat detection strips
• Pneumatic fire detection loop 4. Detecting the Fire
5. Types of Equipment Protected
The best candidates for dry chemical fire suppression systems are industrial a pplications. The agents most commonly employed are ABC or BC type powd er. They are extremely effective fire fighting agents that suppresses fire by co ating the surface of the combusting material. The coating separates the fuel from the oxygen supply, and prevents re-flash.
Typical hazards protected include:
수동
화 재 발 생
자동
화재 발견 감 지 기
누름 스위치 제 어 반
기 동 장 치
개구부 폐쇄 가압용 가스용기
질소15Mpa
압력 조정기 2.5Mpa
분 말 용 기 정압작동장치
메 인 밸 브
선 택 밸 브
