Fire safety:
Heat: It acts as a source of spark and anything that generates heat can start a fire. The heat source can be intentionally hot, such as welding equipment or an oven. But the heat can be caused by the product, such as: abrasion or an electrical short circuit.
Combustible material: The combustible material of the fire does not have to be a known fuel in the form of gasoline or gas. . It may be any kind of combustible material. Combustible materials can be solid (such as paper or wood, fabric), liquid (gasoline, diesel, etc.), or gas (natural gas, gasoline vapor, etc.).
The type of combustible material is also important. Because the fire behavior of different materials during burning is different and therefore the extinguishing means may be different. When we look at the classification of fire, the types of combustible materials should be looked at in more detail.
Combustion: The process in which oxygen and a combustible substance combine with a heat source (creating a spark) and lead to fire.
Oxygen: Oxygen required for combustion is usually supplied from the surrounding air. If oxygen is consumed, the fire will go out. Oxygen can come from other sources such as welding gas, or chemicals from oxidizing agents, which produce oxygen when burned. Fire Classification: Fires are based on the type of substance. Combustibles are classified into 7 groups. This classification is used as a basis for identifying fire extinguishers for different types of fire.
- کلاس A : آتش هایی هستند که شامل مواد جامد به طور معمول با ماهیت ارگانیک مانند زغال، چوب کاغذ و الیاف طبیعی هستند.
- کلاس C : آتش هایی هستند که شامل گازها هستند مانند متان، اتان، پروپان، بوتان و میعانات گازی.
- کلاس D : آتش هایی هستند که ماده سوختنی فلز هست. مانند آلومنیوم، سدیم، پتاسیم و منیزیم.
- کلاس E : آتش سوزی های ناشی از برق و یا وسایل برقی.
- کلاس F : آتش های ناشی از مواد منفجره.
- کلاس K : آتش های ناشی از چربی های خوراکی و سرخ کردن.
Heat transfer and fire spread: When heat is transferred from one substance to another, fire spreads. These processes include transfer, direct method or conduction, indirect method or displacement, radiation or direct burning. Understanding heat transfer methods is important in fire safety.
Guide: Heat transfer is from a material (usually solid) with a high temperature to another material with a lower temperature. . Metals are excellent conductors of heat. If the end of a tablespoon is placed in a container of water, first the part of the metal that is immersed in the water is heated. But over time, the heat transfers to the metal and heats the handle as well. In a fire, heat is transferred by conduction along metal beams and beams, which leads to the spread of fire in buildings.
Displacement: Hot gases are lighter than cold gases, so hot gases created during a fire rise to the top. As the hot gases rise upward, the temperature under the roof rises, leading to combustion. When gases cool, they fall again. As the gases rise and fall, air flow is created. In a fire in a large building, the displacement current may cause rooms on higher floors to become hotter and catch fire.
Radiation: is a term which is used to describe heat transfer by infrared rays. Infrared radiation is the part of the electromagnetic spectrum (the part of light) that cannot be seen but is emitted by hot, glowing materials such as electric heaters, molten metal, and the sun. When a fire burns, it emits radiant heat, which causes the material to heat up far from the initial location of the fire and eventually ignite.
Direct burning: Heat transfer by direct burning occurs when the material that is on fire collides with another material and causes it to catch fire. A good example of direct burning is a lighted cigarette that falls on a sofa and ignites it.
Causes and consequences of a fire in the workplace: A workplace fire starts when heat from an intentional or accidental act acts as a source of ignition on a combustible material. All these types of fires can be prevented by proper safety precautions. A fire can be intentional and the losses caused by a fire can cause heavy financial, human and life costs, and more than 70% of businesses that suffer from a big fire fail within three years.
Human expenses:
- از دست دادن جان چه در اثر حرارت و سوختگی و چه در اثر استنشاق دود و گازهای سمی.
- دود می تواند دید را محدود کرده، باعث لغزش، سکندری خوردن و سقوط در هنگام فرار شود.
Financing Costs:
- خسارت به ساختمان ها از جمله فرو ریختن ساختمان.
- تولید از دست رفته.
- از دست دادن تجهیزات
- سرمایه از دست رفته.
The role and benefits of effective fire risk assessment: Prevention and control of the spread of fire is an important issue and most countries have laws to deal with this threat, for example, requiring fire inspectors and risk assessment. fire However, the employer is responsible for the fire safety of the workplace and must ensure:
- محل کار مجهز به تجهیزات آتش نشانی، دتکتورها و آلارم های حریق است و به آسانی در دسترس، قابل استفاده و بوسیله علائم مشخص شده است.
- اقدامات مناسبی جهت اطفاء حریق، معرفی و آموزش کارکنان جهت اجرای این اقدامات و برقراری ارتباط با سرویس های اضطراری بیرونی وجود دارد.
- مسیرهای اضطراری تمیز نگه داشته می شوند و در انطباق با قوانین و مصوبات مربوط به مسیرها، درب ها و علائم خروج اضطراری هستند.
- اقدامات پیشگیرانه از حریق حفظ و نگهداری شده و در وضعیت کاری خوب هستند. این الزامات ممکن است بوسیله بازرسان ذیصلاح آتش نشانی محلی قابل اجرا باشند.