Enclosure Fire Dynamics - Assignment Example

Running Head: ENCLOSURE FIRE DYNAMICS Student’s Name: Course Code: Lecture’s Name: Date of presentation: A1. The hydrocarbon burns in oxygen to produce carbon dioxide and water. Nitrogen does not decompose in combustion. However, at high temperatures, some nitrogen Combustion in Air Combustion of the chemical in limited air leads to the formation of CO, and soot (C). Stoichiometric: …… (i) If combustion occurs in limited oxygen environment, …. (ii) In further limited oxygen environment, only soot (C), is formed, …..(iii) Yield Yield (CO2) = In the three combustion equations above, RMM of Dimethylnitrosamine (DMN), C2H6N2O is 62, while the RMM of is 44. Combustion Reaction Moles of produced Mass of Yield i 5.5 88 1.41 ii 5 44 0.71 iii 3.5 0 0 Comparing the amount of oxygen consumed in the three equations against the relative stoichiometric amount, gives Reaction Fuel Mass Consumed Oxygen mass consumed i 62 176 1 ii 62 160 1.11 iii 62 112 1.5 Summing up the inert gases together and assuming that the is smaller than the assumption of stoichiometric equation of combustion, gives Air = 79% nitrogen 21% oxygen RMM=0.21*32+ 0.79*28= 28.84 A2. Energy radiated Energy Received Net Energy Exchange - mean emissivity is 0.25 a=8m, b=11m, z=2.25m Therefore, Simplifying and solving, Rate of heat transfer, B1. Superficial Burns This refers to the first degree burns. In this type of burns, the skin is destroyed, but the epidermis (outermost skin layer) is left intact, and therefore able to execute its function in the skin of the body i.e. protecting the inner tissues from injury, infection as well as temperature control. Superficial burns are characterised by; redness, slight pain and no oedema. First degree burns normally heal within seven days. i. Partial-thickness Burns This is also referred to as 2nd degree type of burns and characterised by skin damage extending through the epidermis and into the inner second skin layer; dermis. The presence of second degree burns on a body signifies loss of skin functionality. Partial- thickness burns are manifested by presence of blisters. The destroyed epidermis layer peels off from the inner dermis layer. The blisters eventually spreads away until the thin epidermis layer drops off; exposing the raw dermis layer beneath. The exposed dermis begins to lose body fluids, heat and ability to prevent infection. The exposed dermis nerve cells are the more painful and thus the patient suffers intense pain. ii. Full thickness burns This type of burns is referred as third- degree burns, where both epidermis and dermis are destroyed. The patient suffers loss of heat, body loss, and infection as associated with the second degree type of burns. This kind of burns are characterised by dry, leathery (dark brown or charred) skin, loss of nerve sensation/ little pain. In certain cases the entire dermal tissues and layers may be involved. ‘Eschar’ ‘Eschar’ refers to a slough, or piece of dead tissue that is cast off from the skin surface. Eschar are manifested on the skin surface as; ulcer, gangrene, fungal infection. B2. The workers were exposed to the following gas mixture for 18 minutes before being rescued: Hydrogen cyanide, HCN 62 ppm Carbon dioxide, CO2 2.8% fractional incapacitating dose Answer 22.7% of the dose that would kill 50% of a population The TOTAL FLD is just the sum!! Example but with 2.8% CO2 in the atmosphere!! But NOW we also have HVF = 2.8 A = 0.1 Hence We now expect Read More