1. Thiazole (C3H3NS) occurs natrually as part of vitamin B1 (thiamin) such as in pasta and bread.
Thiazoles have anti-tumor and anti-viral properties but most thiazole compounds are flavourings. If it is combusted perfectly in air the products are carbon dioxide, water, hydrogen sulphide (H2S) and nitrogen.
What is the balanced reaction?
What is the RMM of thiazole?
What is the fuel-air mass ratio?
What is the oxygen depletion?
What is the yield of CO2?
What is the yield of H2O?
What is the yield of N2?
For ideal combustion, what is the yield of carbon-monoxide?
You may assume the composition of air is 21% O2 and 79 % N2. A periodic table is provided overleaf, should you need one.
2. Critically review and distinguish superficial, partial-thickness and full thickness burns and explain the significance of ‘eschar'. How would eschar appear on a Lund-Browder chart?
3. Critically review zone and field models used for compartment fire modelling. Provide examples and critically analyse the main assumptions, limitations, advantages and disadvantages of these models.
4. The underside of a smoky layer 14m x 9m is radiating like a flat, isotropic plate at 510°C to the floor of a compartment 2.15m below. The mean emissivity is 0.41 and the floor is homogenous/flat plate at 35°C. What is the rate of heat transfer from the smoky layer to the floor?
5. A new type of insulating board has been developed by that esteemed construction company Kaput Ltd. They warn that at extremely high heat fluxes it could be ignited, but they don't think it's very likely and it would take hours, so there's no real risk!
As an expert on the ignitability of materials you are asked to perform a thick/thin calaculation given the following data on the material:
Density 2300 kg m-3
Thermal conductivity 0.82 W m-1 K-1
Specific heat capacity 824 J kg-1 K-1
Thickness of board 7mm
Initial/ambient laboratory temperature 18°C
Ignition temperature 410°C
It is considered that if 20 kW m-2 would be enough to ignite most materials (i.e. indicative of flashover fires). Perhaps something easy to ignite would only require 10 kW m-2. Would this material ignite within ten minutes if exposed to 10 kW m-2?