Small-Scale Compartment Fire Experiment and the Effects of Forced Ventilation - Lab Report Example

LAB REPORT: VЕNTILАTIОN SMALL-SCALE COMPARTMENT FIRE EXPERIMENT AND THE EFFECTS OF FORCED VENTILATION Name Course Instructor Institution Location Small-Scale Compartment Fire Experiment and the Effects of Forced Ventilation Introduction Aim: To assess how a compartment fire develops from ignition to flash over and decay Hypothesis If the fire is ignited into the compartment full of fuel and air, the fire can start, grow, flush over, fully developed and decay. A compartment fire is the fire in any enclosed space, and such fire is either; Fuel enclosed in which enough air is available to fully reacts with all fuel in the enclosed place, or; Ventilation enclosure in which there was inadequate air was available, or air was limited to react. Compartment air is in different stages, and these are the ignition stage, growth stage, flush over the stage, and fully developed and decay stage. At the beginning of fire, compartment has no effect on the growth and development of the fire. As fire, there is growth in fire, the smoke and hot gases generated forms the layer of under the ceiling, and this can start to flow out of the compartment, When fire continues with growing and the opening is subtle to move out combustion product at a distance far from the source, at the rate at which they are being produced, the upper layer increases and move down to the floor. The fire can develop, and flashover can happen resulting in the involvement of the compartment. If the fuel in the compartment has been fully consumed, the fire starts to decay until it extinguishes itself because of insufficiency of fuel. Description of experimental equipment Firebox; a firebox is a small-scale compartment constructed from the “mono lux 500”. It is constructed of (roof, floor, and walls) 0.025m thick external layer of “mono lux 500” lining with one wall built using fire resistant glass. The firebox has an adjustable door opening to permit the study of the effect of ventilation size on fire. The floor has one hole in through which an axle passes so as to enable fuel, and it rest on the balance below, to allow the weight of the material to be recorded. The firebox was fixed inside the steel frame with the wheel to permit easy movement if necessary. There were three columns of the thermocouple on the rear wall of the compartment and one thermocouple protruding through the floor hole. Thermocouple; thirteen thermocouples were used in the experiment to measure the temperature. These were type K (nickel-chromium/ nickel-aluminium) with the stainless steel sheet. Temperature of air inside the compartment on the rear wall of the compartment was measured using twelve thermocouples and the thermocouple protruding through the floor hole. The thermocouple was projected into the firebox and positioned in three columns to the squirrel date logger to record the temperature of the compartment. Apparatus used in the experiment Fuel (PMMA) Fuel support Thermocouples (thirteen thermocouples) A firebox Ignition source the firebox was built from “mono lux 500” and it was constructed of (roof, floor, and walls) 0.025m thick external layer of “mono lux 500” lining with one wall constructed using fire resistant glass. The firebox was used as the small fire compartment for measuring the effect of forced ventilation the thermocouple was placed in three columns to the squirrel date logger to record the temperature of the compartment. Fuel was used to produce fire in the presence of sufficient air, and the ignition was used as a source of fire. Fuel support was used to support fuel Methodology the method used was the same as that of the laboratory sheet. The dimension of the firebox and the thickness of mono lux, the position of the thermocouples and the location of thermocouples were measured and recorded in the laboratory booklet. The dimensions of the two fans and their velocities were measured and recorded. The height of the fans location in their rear location of the firebox were also measured and recorded. All thermocouples were cleaned in so that the reading could not be affected by the soot or dirt deposits Thermocouples were connected to the require data logger and the channel that applied to a particular thermocouple (their location within the firebox) were recorded. The dimension of the sample fuel (PMMA) was measured and recorded. While ensuring that the balance was switched on, the fuel was placed on the tray and the tare button was pressed to set the reading to zero. The fuel was placed on the tray and 5g of PMMA powder was added. The purpose of adding PMMA powder was to enable fuel slab to ignite and spread the fire faster through the whole surface of the PMMA. The mass of PMMA fuel was recorded. A suitable table was created was created in the lab book for the purpose of recording the weight of the test (was approximately after 30 – 40 minutes) While ensuring that the extract system was switched on, the data logger was started, and the fuel was ignited. The sample of paper was put in the firebox just to the vent opening, and the observations were recorded. After 2 to 3 minutes, the fun was started, and the weight of the place of filter paper was recorded after approximately 5 minutes, the filter was held at the opening using tongs for2 minutes the filter paper was weighed, and its weight was recorded. This procedure was repeated at regular interval of time, and the observations were recorded The Squirrel data logger was stopped after the fire ceased. Results Experiment 1 Velocity of the fan = 10 m/s Time = 17 minutes Position and nature of ignition = fire became bigger and the small part of the tray melted at 19 minutes when the smoke height was 48.8 cm Decomposition of soot = decomposition of soot was high because almost all parts were burnt Time/ minutes Smoke height/ cm Observation 17 57.2 The fire became bigger 18 51.6 The fire became smaller 19 48.8 The tray became melted 20 40.4 21 35.0 22 30.2 Small part evaporated 24 25.4 25 17.4 26 14.0 27 11.2 Part close then shut down 28 8.8 29 7.0 30 5.6 31 4.4 32 3.2 33 3.0 Almost all are burnt 34 2.8 Burning stopped Flashover was not achieved since the maximum temperature was below the minimum temperature (5000C) for flashover to occur. Back draught was not achieved since there no extra oxygen introduced into firebox during combustion Experiment 2 Velocity of the fan = 8 m/s Time = 1582.6 minutes Position and nature of ignition = fire had fully developed and it reached the roof Decomposition of soot = the smoke height increased with reduction in time taken meaning the level of decomposition was high as time goes on. Time/ minutes Smoke height/ cm Observation 1568.1 2 1582.6 3 1565.9 6 1564.2 5 1561.9 8 1558.7 12 1554.0 14 1546.8 23 All the surface of the same was on fire 1532.9 24 1509.0 26 Fire fully developed 1479.2 27 Fire reached the roof 1458.2 28 1430.8 30 1394.0 30 1354.0 31 Full point burning Flashover was not achieved since the maximum temperature was below the minimum temperature (5000C) for flashover to occur. Back draught was not achieved since there no extra oxygen introduced into firebox during combustion Experiment 3 Velocity of the fan = 6 m/s Time = 3 minutes Position and nature of ignition = surface of the sample was on fire Decomposition of soot = decomposition increases as time increases as indicated in the table Time/ minutes Mass /g Observation 1 1575.2 2 1574.3 3 1570.3 4 1565.5 30 cm/ surface of sample was on fire 5 1558.2 6 1548.9 7 1538.6 Fire slowed down 8 1526.4 Fire never reached the peak, combustion was lamina 9 1524.8 10 1514.9 11 1503.8 12 1492.2 Flashover was not achieved since the maximum temperature was below the minimum temperature (5000C) for flashover to occur. Back draught was not achieved since there no extra oxygen introduced into firebox during combustion Experiment 4 Velocity of the fan = 5 m/s Time = 6 minutes Position and nature of ignition = the fire was spreading at a high rate Decomposition of soot = as the time increases the mass of PMMA was reducing as shown in the table Time/ minutes Mass /g Height of smoke 1 1554.1 8 2 1533.2 7 3 1552.7 2 4 1552.5 2 5 1552.0 2.3 6 1551.6 2.3 7 1551.2 3.4 8 1550.6 3.4 9 1549..1 5 10 1548.1 5 11 1547.1 6 12 1545.9 7 13 1544.6 8 14 1543.2 10.1 15 1541.4 11.6 16 1540.0 21 17 1538.1 21 18 1536.1 21.2 19 1534.0 22 20 1531.6 23 21 1529.2 23 23 1526.4 22 24 1523.5 22 25 1520.4 21 26 1517.0 21.6 27 1509.3 21.5 28 1504.3 25 29 1498.5 25 30 1491.4 30 31 1487.5 30 32 1485.0 30 33 1483.9 30 Flashover was not achieved since the maximum temperature was below the minimum temperature (5000C) for flashover to occur. Back draught was not achieved since there no extra oxygen introduced into firebox during combustion Experiment Door height (cm) Door width (cm) Fuel area (m2) (HxW) Original mas of fuel (g) Flashover achieved Yes/ No Back draught achieved Yes/ No 1 22.5 15.0 0.034 1558.7 No No 2 22.5 15.0 0.034 1559.8 No No 3 22.5 15.0 0.034 1574.1 No No 4 22.5 15.0 0.034 1552.8 No No Discussion In an experiment, 1combustion was high, rising at the interval of time increase. The fire became bigger up to the extent of melting the tray. As burning/ combustion continued the maximum point was reached, and the level of combustion reduced gradually until fire became subtle. Almost all parts got burnt meaning the oxygen available was sufficient to complete all fuel in the firebox. From the graph, the temperature rise was proportional to time increase of From the table results, burning reduces as the mass was reducing the time was increasing, and the smoke height also reduced with increase in time For experiment 2, fire fully developed and combustion was at maximum the height of smoke was increasing with the increase in mass From the plot, temperature increases with the reduction in time Both the temperature was not so high to achieve the flash point and back draught For experiment 3, the mass of the sample reduced with the increase in time due to combustion in the firebox. From the graph, the temperature increased with increase in time since burning started at a low level and continued rising with time. Combustion level was low making the temperature achieved to be a bit low for it to meet the flash and back draught points For experiment 4, the mass of the sample reduces as combustion increased with increase in time, the height of smoke rise to the maximum to the end of combustion as the mass of the sample was reduced. In experiment 4, the combustion temperature was higher than all those other three experiments making it gain a higher temperature than experiment as. Conclusion The experiment was successfully carried out using the meter provided on the lab sheet. The experiment agreed with the theory. The experiment needs to be done again if the flash point and back draught is to achieve and this time some opening should be allowed for extra oxygen to enter the firebox. In the experiment burning worked well but combustion did not work well because flash point and back draught were not achieved. Flashover was not achieved because the temperature obtained during experiments was less than the minimum temperature (i.e. 5000C) at which the flashover can be achieved. An opening should be provided in future in the firebox for full combustion to take place Read More

These were type K (nickel-chromium/ nickel-aluminium) with the stainless steel sheet. Temperature of air inside the compartment on the rear wall of the compartment was measured using twelve thermocouples and the thermocouple protruding through the floor hole. The thermocouple was projected into the firebox and positioned in three columns to the squirrel date logger to record the temperature of the compartment. Apparatus used in the experiment Fuel (PMMA) Fuel support Thermocouples (thirteen thermocouples) A firebox Ignition source the firebox was built from “mono lux 500” and it was constructed of (roof, floor, and walls) 0.

025m thick external layer of “mono lux 500” lining with one wall constructed using fire resistant glass. The firebox was used as the small fire compartment for measuring the effect of forced ventilation the thermocouple was placed in three columns to the squirrel date logger to record the temperature of the compartment. Fuel was used to produce fire in the presence of sufficient air, and the ignition was used as a source of fire. Fuel support was used to support fuel Methodology the method used was the same as that of the laboratory sheet.

The dimension of the firebox and the thickness of mono lux, the position of the thermocouples and the location of thermocouples were measured and recorded in the laboratory booklet. The dimensions of the two fans and their velocities were measured and recorded. The height of the fans location in their rear location of the firebox were also measured and recorded. All thermocouples were cleaned in so that the reading could not be affected by the soot or dirt deposits Thermocouples were connected to the require data logger and the channel that applied to a particular thermocouple (their location within the firebox) were recorded.

The dimension of the sample fuel (PMMA) was measured and recorded. While ensuring that the balance was switched on, the fuel was placed on the tray and the tare button was pressed to set the reading to zero. The fuel was placed on the tray and 5g of PMMA powder was added. The purpose of adding PMMA powder was to enable fuel slab to ignite and spread the fire faster through the whole surface of the PMMA. The mass of PMMA fuel was recorded. A suitable table was created was created in the lab book for the purpose of recording the weight of the test (was approximately after 30 – 40 minutes) While ensuring that the extract system was switched on, the data logger was started, and the fuel was ignited.

The sample of paper was put in the firebox just to the vent opening, and the observations were recorded. After 2 to 3 minutes, the fun was started, and the weight of the place of filter paper was recorded after approximately 5 minutes, the filter was held at the opening using tongs for2 minutes the filter paper was weighed, and its weight was recorded. This procedure was repeated at regular interval of time, and the observations were recorded The Squirrel data logger was stopped after the fire ceased.

Results Experiment 1 Velocity of the fan = 10 m/s Time = 17 minutes Position and nature of ignition = fire became bigger and the small part of the tray melted at 19 minutes when the smoke height was 48.8 cm Decomposition of soot = decomposition of soot was high because almost all parts were burnt Time/ minutes Smoke height/ cm Observation 17 57.2 The fire became bigger 18 51.6 The fire became smaller 19 48.8 The tray became melted 20 40.4 21 35.0 22 30.2 Small part evaporated 24 25.4 25 17.4 26 14.0 27 11.

2 Part close then shut down 28 8.8 29 7.0 30 5.6 31 4.4 32 3.2 33 3.0 Almost all are burnt 34 2.8 Burning stopped Flashover was not achieved since the maximum temperature was below the minimum temperature (5000C) for flashover to occur. Back draught was not achieved since there no extra oxygen introduced into firebox during combustion Experiment 2 Velocity of the fan = 8 m/s Time = 1582.6 minutes Position and nature of ignition = fire had fully developed and it reached the roof Decomposition of soot = the smoke height increased with reduction in time taken meaning the level of decomposition was high as time goes on.

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