Our website is a unique platform where students can share their papers in a matter of giving an example of the work to be done. If you find papers
matching your topic, you may use them only as an example of work. This is 100% legal. You may not submit downloaded papers as your own, that is cheating. Also you
should remember, that this work was alredy submitted once by a student who originally wrote it.
The paper “Experiment on Fire Box” is a perfect variant of a lab report on environmental studies. The aim of the experiment was to study the stages of fire development inside an enclosure in relation to a real fire situation. This was accomplished by burning a Polymethyl methacrylate (PMMA) in a firebox in the laboratory…
Download full paperFile format: .doc, available for editing
Name
Course
Date
Table of Contents
Table of Contents 2
Aims 3
Apparatus 3
Methodology 3
What was measured and accuracy 4
Data obtained, explanation & analysis of data 4
Personal observations 6
Explanation & analysis of data 7
Evaluation of the experiment 7
Conclusion 8
Experiment on fire box
Aims
The aim of the experiment was to study the stages of fire development inside an enclosure in relation a real fire situation. This was accomplished by burning a Polymethyl methacrylate (PMMA) in a fire box in the laboratory.
Apparatus
The fire box
The apparatus were arranged in a fire box as shown in the figure below.
Figure 1 shows the measurement of the firebox
The firebox was made of Monolux 500 insulating material whose thickness was 25mm. 12 thermocouples were placed in the firebox in a regular pattern and PMMA were near the centre as shown. The sizes of cross section of PMMA used were 100 x 100mm and 200 x 200mm. The temperatures were recorded every two seconds with the help of squirrel data logger. The change in mass was also recorded at an interval of 30 seconds.
Methodology
PMMA was mixed with petroleum gel before pouring on the fuel and placing them on a metal plate. The plate placed 130mm away from the opening and connected to the balance to measured the change in mass. Thermocouples were also placed evenly inside the compartment and connected to squirrel data logger to record the temperature. Finally, the fuel was ignited using a torch and left to burn till the fire went off by itself.
What was measured and accuracy
The temperature in the firebox was measured through the use of 12 thermocouples that was places at regular ponts inside the firebox. Thermocouples had an accuracy of 0.10C. Inconel was install in the firebox to record the data and to measure the accuracy.
Data obtained, explanation & analysis of data
Figure 2: Graph 01 Temperature of the thermocouples
From the graph it can be seen that the temperature varies at different parts of the firebox. The temperature recorded by the thermocouples 1, 2, 5, 6, 9, 10 are lower since they are located at a point lower than level of the fuel bed as shown in the figure 1 above. There temperatures ranged between 0 and 3500C. Thermocouples 1, 5, and 9 show the lowest temperatures, with thermocouple 1 being the lowest of the three. Thermocouple 1 was located far from the fuel bed. Thermocouple 5 was placed below the fuel bed where cool air (drawn by the plume rising towards the ceiling due to buoyancy) flows (Barham, 2006). Temperature spikes seen in thermocouple 5 at an end of the developing stage were due to flame impingement. Thermocouples 3, 4, 7, 8, 11, and 12 show the highest temperature as they were located in the region by the generated thermal smoky layer. Thermocouple 8 show the highest temperature as it was located directly above the fuel bed and also at the region where thermal smoky layer are generated. The temperature spikes may be due to the direct impingement by the flame. The mass flow of the compartment resulted in rise in temperature for thermocouple 12. Thermocouple 9 also has low temperature as it is located near the ventilated opening where cool air flow into the firebox. The highest temperature reached is 3200C.
Figure 3: Graph 02 Temperature of the thermocouples
The temperatures range in this experiment was between 0 and 5500C. Thermocouples 1, 5, and 9 show the lowest temperatures, with thermocouple 5 being the lowest of the three. Thermocouple 5 was directly placed below the fuel bed where cool air flows. Thermocouples 1 and 9 were located at far ends from the fuel bed. Thermocouple 1 was the second lowest as it was located at a far end from the fuel bed. Thermocouple 9 was located near the ventilated opening where cool air flow into the firebox. The highest temperature was 8000C.
Personal observations
Time line and personal observation from the experiment
Incipient stage
Time (s)
Time (s)
Observation made
100 mm PMMA
200 mm PMMA
0 - 5
0 - 5
The fire was ignited on PMMA
50
10
Smoke started being produced from the fuel.
100 - 200
50 - 100
The fire started to grow and it started cracking sound as the colour change to orange.
Growth stage
Time (s)
Time (s)
Observation made
100 mm PMMA
200 mm PMMA
250 - 700
200 - 700
The length of the flame and smoke increased, and most parts of the fuel bed was covered by the flame
Fully developed stage
Time (s)
Time (s)
Observation made
100 mm PMMA
200 mm PMMA
700 – 1400
700 - 1400
The smoke was seen to be floating and covered the ceiling, the fuel bed was covered with flame and the smoke moved out of the door.
Decay stage
Time (s)
Time (s)
Observation made
100 mm PMMA
200 mm PMMA
1450 - 1700
1450 - 1700
The fire began to reduce in size and the smoke produced started to decrease
1750
1750
The flame went off, and the all the fuel was consumed
Explanation & analysis of data
Mass loss rate and Heat release Rate in different stages of fire
Figure 4
For 100x100 mm PMMA a rapid mass loss rate was recorded between 800 and 1500 seconds. For 200x200 mm PMMA a rapid mass loss rate was recorded between 600 and 1500 seconds.
Ignition stage
This is the initial stages of development as shown in figure 2 and 3. Figure four show mass loos rate for the two PMMA. The mass loss rate increased with time. The rate was low at the beginning since fire took time to penetrate through the thick skin of PMMA.
Developing stage
The mass loss rate at this stage started to increase.
Fully growth stage
This stage showed fairly constant mass loss rate. High heat release rate was also recorded at this stage.
Decay stage
From 1500 to 1700 seconds it showed the highest rate of heat loss rate. The mass loss rate also slowed down as the mass near zero.
Evaluation of the experiment
The four stage of development of fire, which include ignition, growth stage, fully developed stage and decay has been noticed. At a fully developed stage, the upper and the lower layers are visible from the temperature time graph. The temperature at the upper portion of the enclosure was uniform. This may have been contributed by the small space available in the firebox. The temperature is expected to vary over the entire space in complex or large buildings. In enclosures with ventilation controlled fires, where highest temperature is observed near the supply of air (Drysdale, 2011; Nag, 2008).
Time for thermal penetration, tp on the wall is calculated as follows
The thickness of the firebox = 25mm
Heat transfer coefficient is calculated as follows.
672K
Conclusion
Three stages for fire develop development has been shown in the experiment. The amount of heat released in the experiment was too small to enable flashover that usually occurs between the developing stage and fully developed stage. The upper layer requires a temperature of 6000C for flashover to occur.
References
Barham R., (2006). Fire Engineering and Emergency Planning: Research and applications, Routledge
Bergman, T. L., & Incropera, F. P. (2011). Fundamentals of heat and mass transfer. Hoboken, NJ: Wiley.
Bjorn Karlsson, James Quintiere, (1999). Environmental & Energy Engineering, CRC Press
Drysdale, D. (2011). An introduction to fire dynamics. Chichester, West Sussex: Wiley.
Enclosure Fire Dynamics
Nag, P. K. (2008). Engineering thermodynamics. New Delhi: Tata McGraw-Hill.
Read
More
The author states that the first experiment evaluated the time needed for the initial labeling process along with the labels' size.... The second experiment focused on assessing the time needed to determine the different relationships.... The third experiment evaluated the queries' response times before and after insertions.... This means that relying on only a few tests for each experiment in the design of the new scheme could hamper the credibility of outcomes negatively (quote)....
A fire burning in an open space will entrain air from all sides which creates an imbalance in the airflow.... Samples that melt or shrink away from the fire without igniting are held in the second specimen holder.... (B) Lab Cone The importance of this experiment is its ability to identify the heat release rate of experimental fires as well as other important factors such as heat of combustion, ignition time, levels of carbon monoxide and carbon dioxide, and the amount of smoke present in the fire....
0 whole surface of the material was on fire.... This report "Small-Scale Compartment fire Experiments" discusses the general trend of the mass reducing with time but in some incidences, the mass appears to rise before dropping again.... 0 level of fire was noticed to rise and at 1.... At the early stages of the fire, the compartment has a negligible effect on the fire development.... As the growth of fire continues the smoke and hot gases generated form a layer below the ceiling and this results in the gases flowing out of the compartment....
The "Bang box and Flash Point" paper analyzes a fuel system and the possibility of an explosion of the fuel-air mixture as the result of the arcing or ignition source.... he mixtures of dispersed materials that are combustible, (for example, vaporized fuels, gaseous, and little fine particles) with gasses shall hold fire burning when fuel concentration is in the range of a clearly demarcated lower and the upper limits obtained via research (experiment), known as the limits of flammability and sometimes it is called the limit of explosiveness....
According to research findings of the paper 'Transient Flame Spread Out of Small Scale fire box', it has been seen that the amount of fuel burning will dictate the amount of mass loss rate and this would, in turn, bring about high temperature in the combustion chamber.... The ejection of flames can be intense and sudden and may result in the rapid spreading of fire to other compartments.... This scenario results in where the objects within direct proximity of the rooms get burnt resulting in quick spreading of fire to even outside the building....
The primary objective of the research gets achieved through burning PMMA inside the fire box in the laboratory.... Figure 1 –Side view of fire box with thermocouples showing nominal measurementsThirteen thermocouples, mounted on three columns (positioned at 0.... igure 2 –fire box front view, full and half- sized opening showing nominal measurementsMethodology (5 marks)The following is the generic procedure used for conducting the experiments....
The paper "fire box Experiment" tells us about study the different stages of fire development.... The experiments were conducted in a controlled fire box complete with all components of the fire triangle.... The onset of the experiment was marked by setting the fuel on fire which was done using a torch.... The fuel is placed on a stainless steel tray which is supported by an axle passing through a tight hole drilled on the floor of the box....
The author outlines the characteristics' of the material as it is consumed in flames in the combustion box.... This work called "fire Experiment" describes the relationship between the rate at which fire spreads in a given area in comparison with the temperatures to the given area.... The two thermocouples that were very close to the source of heat the fire were the seventh and eighth thermocouple showed the highest temperatures too from the experiment....
6 Pages(1500 words)Report
sponsored ads
Save Your Time for More Important Things
Let us write or edit the lab report on your topic
"Experiment on Fire Box"
with a personal 20% discount.