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Explosion Hazard And How To Prevent It?
Let's Today We Know About Workplace Explosion Hazard And How To Prevent Explosion Hazard?
Of course, an explosion is a physical change that is due to a chemical reaction or physical change. That means any explosion must have a physical change.
Physical Explosion: -
A physical explosion occurs if a physical process (Compression, Heating, etc) releases so much energy in an enclosed space that the blasting pressure is exceeded. For example, when a compressed gas cylinder is placed near a heater, a physical explosion may occur. A cylinder that contains liquefied gases is particularly sensitive. Near place a gas cylinder in the vicinity of a heater.
Chemical Explosion: -
A chemical explosion occurs as the result of a pressure increase caused by the energy released by a chemical reaction.
This can be defined as an exothermic reaction Associated with a rapid pressure rise.
The Lower Explosion Limit (LEL): -
The lower explosion limits the lowest concentration (in volume ‰ ) of flammable gas or vapor in the air, at which the gas/air or vapor/air mixture is explosive.
The Higher Explosion Limit (HEL): -
The higher explosion limit is the highest concentration (in volume ‰ ) of flammable gas or vapor in the air, at which the gas/air or vapor/air mixture is explosive.
For solids, explosion limits are given gm Solids/m³ air. The below list shows the explosion limit of a few common fuels Or chemicals.
Explosion limit of Gases and Vapors in the air (in volume ‰ ).
| Compound | Lower Explosion Limit | Higher Explosion Limit |
| Methane | 05.00 | 15.00 |
| Hydrogen | 04.00 | 74.20 |
| Acetylene | 02.50 | 80.00 |
| Ammonia | 15.50 | 27.00 |
From the table above we can understand that Methane's Lower Explosive Limit (LEL) is 05% and Upper Explosive Limit or Higher Explosive Limit (HEL) is 15% i.e. 5% with Methane and the remaining 95% is in combination with Methane Lower Exclusive Limit (LEL) and if 15% is in Methane and 85% in Air. Is the Explosive Limit or Higher Explosive Limit (HEL).
Explosion Protection: -
It is essential to distinguish between physical over-pressurization, which is a process occurring over a significant time period, And explosions in which the peak pressure is raised in milliseconds. The measures to avoid, or limit the effects of, the explosion are therefore quite different. They include: -
- Containment,
- Suppression,
- Venting (equipment and/ or building),
- Partial Containment by blast walls, or Shields.
Containment: -
Because of the large over-pressure generated by explosions, it is not usually feasible to design equipment for containment; the expectation is small laboratory-scale apparatus. Specific areas of buildings, e.g. Autoclave rooms, may be built to contain explosions. Reinforced concrete walls exceeding 30-centimeter thick and a roof of similar thickness are necessary for containment of explosive blast impulse and to resist missile penetration.
Explosion Relief-Buildings: -
Proces with an inherent explosion hazard should whenever practicable be located in the open air or in open-sided structures. If the hazard exists in an enclosed building, e.g. with pilot plants or factories filling LPG cylinders or aerosol cans, explosion relief may be desirable. The relevant areas are generally restricted by Walls to limit the effects of a vented explosion and the vents themselves have to be cited with regard to the safety of personal, equipment, etc. outside
vents are positioned as near as practicable to predictable points of origin of explosions and require careful sizing.
The types of vents include; -
- Blow-out Panel,
- Hinged Panel,
- Unrestricted openings/ louvers,
- Large, Outwards-opening, doors with a weak latching device.
Explosion Suppression: -
Explosion Suppression system permits a flammable atmosphere to exist in equipment but if ignition occurs it is detected almost instantaneously and a suppression agent is quickly injected during the period of flame propagation when the rate of pressure rise is relatively slow. Hence a hazardous over-pressure is avoided.
The technique is equally applicable to gas, vapor, mist, or dust explosion prevention. The most common agent used is ChloroBromoMethane, but other Halons may be selected for specific uses; powder suppression agents, e.g. ammonia hydrogen phosphate, are also available. Advanced entering may also be used. The injection of agents such as nitrogen or carbon dioxide into connecting ducts prevents flame propagation between different units. A combination of venting and advanced inserting.
# The below list shows the IGNITION TEMPERATURE (ºC) of a few common fuels Or chemicals.
| CHEMICALS/MATERIALS | CHEMICAL FORMULA | IGNITION TMPERATURE (ºC) |
| Acetylene | C2H2 | 305 |
| Ammonia | NH3 | 630 |
| Hydrogen | H2 | 560 |
| Methane (Natural Gas) | CH4 | 595 |
| Benzene | C2H6 | 580 |
| Carbon-disulphide | CS2 | 102 |
| Hydrogen Cyanide | HCN | 535 |
| Ethyl Ether | (C2H5)2O | 170 |
| Ethylene | C2H4 | 425 |
| Gasoline | | 220-450 |
| Wood | | 220-280 |
| Petrol | | 280 |
| Polyethylene | | 240 |
| Match Head | | 80 |
# The below list shows the FLASF POINT (°C) of a few common fuels Or chemicals.
| CHEMICALS/MATERIALS | CHEMICAL FORMULA | FLASHPOINT (°C) |
| Acetic Acid Glacial | CH3-COOH | +40 |
| Acetone | (CH3) 2CO | -18 |
| Acetonitrile | CH3-CN | +02 |
| Aniline | C6H5-NH2 | +76 |
| Benzene | C6H6 | -10 |
| Carbon-disulphide | CS2 | -30 |
| Carbon tetrachloride | CCl4 | NF |
| Chloro benzene | C6H5-Cl | +29 |
| Chloroform | CHCl3 | NF |
| Diethyl Ether | (C2H5) 2-O | -40 |
| Diethyl Amine | NH (C2H5)2 | -39 |
| Digol | O (CH2CH2OH) 2 | +123 |
| Methanol | CH3-OH | +12 |
| Toluene | C6H5-CH3 | +4.4 |
Below I share links to Amazon's essential fire extinguishers so we can all use them as a warning against fire accidents in our workplace or to present you Amazon's best products for example.
# Elide Fire Ball, Self Activation Fire Extinguisher, 2018 New Version, Boat Extinguisher, Car Extinguisher, Fire Safety Product, Elide, 5 Year warranty.
# Smoke and Carbon Monoxide Detector - with LCD Display, Battery Operated Smoke CO Alarm Detector Combo Unit
# Neiko 10908A Fiberglass Welding Blanket and Cover, 4' x 6' | Brass Grommets For Easy Hanging and Protection.
# Safety Technology International, Inc. STI-6400 Exit Stopper Multifunction Door Alarm, Helps Prevent Unauthorized Exits or Entries Through Emergency Doors.
# Novelty Printed Fake Fire Alarm Printed Light Switch Cover
# DIBBATU Fire Blanket Emergency for Kitchen, Suppression Flame Retardant Safety Blanket for Home, School, Fireplace, Grill, Car, Office, Warehouse (8 Pack).
# Honeywell North 7600 Series Niosh-Approved Full-Facepiece Silicone Respirator, Med/Large (760008A).
# Xtend & Climb Pro Series 785P+ Telescoping Ladder, Blue
# Emergency Fire Escape Ladder, Portable Ladder With Anti-Slip Rungs And Wide Steps V Center Support, Easy To Deploy & Easy To Store (5/6 Story - 50 Foot).
# Orbit 57946 B-have Smart Indoor/Outdoor 6-Station WiFi Sprinkler System Controller.
Please take a look at the following links:
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