Mechanical Enggering

The Marcet boiler is a device that is used for the understanding of the basic properties of saturated steam to superheated steam.
Figure 1.1: The Marcet Boiler
The given apparatus was developed for investigating the relationship between the pressure and temperature of saturated steam, in equilibrium with water. The data is then tabulated so that the results can be observed. Initially, the discovery of this phenomenon is founded by Rudolf Clausius, a German physicist that was a thermodynamics power icon. In this experiment, we will further discover the properties of steam, superheated steam and its relation to pressure. OBJECTIVES

To determined the relationship between Pressure and Temperature of saturated steam in equilibrium with water. PROCEDURES
1.The valve M was open and a water supply hose was connected to it. The supply was shut off when the water starts to flow out from the overflow valve M. 2.Water was allowed to flow out.
3.When the boiler drain out 3 liter of water to the tray provided, the valve M was closed. 4.Mercury in glass thermometer was placed into the thermometer well. 5.The power supply was switched ON.

6.The water starts to boil and generated steam for 10-30 minute. 7.As the temperature start to build up, the reading of pressure against temperature was taken. 8.When pressures relieve valve blows off steam, the electrical power supply was switched OFF. 9.The Marcet Boiler was allowed to cool by itself.

10.A reading was taken when the pressure and temperature were dropping. 11.The temperature was converted into degrees Kelvin.
12.A graph of temperature against pressure was plotted.
The Apparatus

Figure 1.1: Marcet Boiler Apparatus
DATA AND ANALYSIS
Table 1.1: Data Collection
Pressure (bar)Temperature °C
(Pressure Increasing)°KTemperature °C
(Pressure Decreasing)°K
035308128401
0.558331132405
160333136409
1.579352140413
290363144417
2.5100373150423
3112385154427
3.5128401158431
4136409160433
4.5142415162435
5154427166439
5.5158431168441
6160433170443
6.5162435172445
7164437172445
7.5166439172445
8168441172445
8.5169442172445
9170443173446
9.5171444173446
10173446173446

Graph 1.1: Pressure Increasing

Graph 1.2: Pressure Decreasing

Table 1.2: From Steam Table
Pressure (bar)Temperature °C
(Pressure Increasing)Pressure (bar)Temperature °C
(Pressure Decreasing)
0000
0.0563352.5450128
0.1817582.8685132
0.1995603.2245136
0.4553793.6154140
0.7018904.0437144

Graph 1.3: Pressure Increasing

Graph 1.4: Pressure Decreasing

DISCUSSION
Result
•We compared the results obtained from conducting the experiment with the steam table. Although there is a slight difference in value of temperature to pressure, we can say that both the steam table and the results obtained have similar patterns. •The most noticeable difference would be from 0 to 2 bar, whereby the in the steam table, the initial temperature increment begins from 0, whereas, from the results obtained, the initial temperature is 35. Possible Errors

•The thermometer which we use to measure the heat was faulty. It is not durable at all. •If excessive water is filled in the boiler, a rapid increase in pressure will result although the temperature has reached its peak. Thus, defeating the purpose of the experiment. •Pressure relieve valve has to be controlled manually since the pressure fails to fall down proportionally to the temperature drop. This has been tedious and dangerous since the pressure relief valve is too hot to be controlled by hand. If the pressure is not allowed to fall with the pressure relief valve, it will take a long time for the pressure to naturally return to 0 bars. Recommendation and Precautions

•Incorporation of a more durable thermometer is much appreciated. Since the thermometer will withstand heavy abuse. •Water has to be filled according to the recommended volume. •Pressure relieve valve has to be altered so that it can be handled easily without risk of harm. CONCLUSION

As a conclusion, we can say that the temperature of a liquid(in this case water) is directly proportional to its pressure. REFERENCES
Lab sheet
Lecturer notes
http://www.efunda.com/materials/water/steamtable_sat.cfm