CHEMICAL ENGINEERING LABORATORY

CHE331

TITLE : MARCET BOILER

GROUP : A6

POSITION NAME ID. NUMBER

PLANNER ORLANDO JIMLI PERIJIN 2011331035

EXPERIMENTER

MUHAMMAD SYAKIRAN IKHWAN BIN ZAKARIA

2011955115

ANALYZER NURUL SYAHEERAH BINTI CHE HASNAN

2011768091

CONSULTANT NURUL SUHAILA BINTI JAMAL

CHEMICAL ENGINEERING LABORATORY REPORT EVALUATION SHEET

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Group 6

Experiment: MARCET BOILER

PLANNER : ORLANDO JIMLI PERIJIN

SCOPE CRITERIAFULL

MARKS MARKS

INTRODUCTION General overview about the experiment 5

Aims/objectives Based on experiment in paragraph form 5

Theory Brief summary from the theory given; add additional data from resources

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Total:

Checked by:

EXPERIMENTER: MUHAMMAD SYAKIRAN IKHWAN BIN ZAKARIA

SCOPE CRITERIAFULL

MARKS MARKS

Diagram and description of apparatus

Include the description of main apparatus, as well as sketched diagram

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Methodology/procedure

Simplified procedures based on what we have been done in lab

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Reference/appendix -extra information extracted/gathered from books/journal -complete raw data and appendices

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Total:

Checked by:

ANALYZER: NURUL SYAHEERAH BT CHE HASNAN

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SCOPE CRITERIA FULL MARKS

MARKS

RESULT -data must be similar with what was obtained during experiment -produce graph/figures based on the data obtained

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discussion Discuss what the result and data mean; discuss and relate the result obtained with the theory

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Total:

Checked by:

CONSULTANT: NURUL SUHAILA BT JAMAL

SCOPE CRITERIA FULL MARKS

MARKS

Abstract Must provide the objective of the experiment, procedure, result and conclusion.

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Sample calculation - Sample of calculation of each variable- Present data accordingly

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conclusion Relate the result obtained with the objective of the experiment

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Recommendation -any improvement to be suggested by observing the inconsistencies observed in result/conclusion

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Total:

Checked by:

ABSTRACT

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This experiment was carried out to determine the relationship between the pressure and

the temperature of saturated steam in equilibrium. Besides that this experiment was

also done to demonstrate the vapor pressure curve. The market Boiler was used for this

experiment. When the pressure increases, the temperature also increases. Therefore,

the relationship of pressure and temperature is directly proportional. The

derived formulae and the data were used to calculate the slope. The dT/dP measured

was compared with the data in the steam table. Theoretically, the values measured

should be almost the same with the predicted values. However, at certain points, the

values are not the same. This may because of the errors made in the experiment.

TABLE OF CONTENTS

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Introduction6-7

Objectives7

Theory8-9

Diagram and Description of Apparatus10

Experimental Procedures11-12

Results13

Sample calculations14-15

Discussion16

Conclusion17

Recommendation17

References18

Appendices19 -

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1.0 INTRODUCTION

Thermodynamics is a part of physics, which deals with work energy andpower of a

system. Thermodynamics mainly works with large-scale system, which can

be measured by experiment study of liquid or gas or the properties of fluid is also a part

of thermodynamics.

Marcet boiler was made by Nathan Chamberlain, Boston, USA, in the year1850.

He made this boiler for measuring the vapor pressure of saturated liquid. Later this

Marcet boiler was used to study the evaporation filtration of water. Pressure and

temperature are two fundamental quantities of materials in thermodynamics. These two

factors have relation directly proportional to each other.

Thermodynamics is defined as a study related to the transfer of heat and work between

a system and its surrounding, undergoing a process causing any of the properties of the

system change.

An ideal gas obeys the equation of state that relates the pressure, specific volume or

density, and absolute temperature with mass of molecule and the gas constant, R.

PV=mRTM

However, real gas does not absolutely obey the equation of state. A few changes on the

ideal gas equation of state allow its application in the properties of real gas.

When energy increases within water, the increasing of activities among the molecules

enables the increase in the number of molecule escape from the surface until an

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equilibrium state is reached. The state of equilibrium depends on the pressure between

the water surface and steam. At lower pressure, the molecules become easier leaving

the water surface while less energy required in achieving the state of equilibrium (boiling

point). The temperature where equilibrium occurs at a given pressure level is called

saturated temperature.

2.0 OBJECTIVES

- To demonstrate the relationship between the pressure and temperature of

saturated steam in equilibrium.

- To demonstrate of the vapor pressure curve .

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3.0 THEORY

Thermodynamics study about the interchange of heat and work between a

system and the surroundings which occurs when the system undergoes a process.

Thermodynamic also concerned about the changes in the properties of fluid. Most

thermodynamics substances such as gases and vapors are often referred as P-V-T

substances .An ideal gas obeys the equation of state that relates the pressure,

specific volume or density, and absolute temperature with mass of molecule and

the gas constant, R. However, real gas does not absolutely obey the equation of

state. A few modifications on the ideal gas equation of state allow its application in

the properties of real gas. When energy is added within water, the increasing of

activities among the molecules caused the increase in the number of molecule

escape from the surface until an equilibrium state is reached. The state of

equilibrium depends on the pressure between the water surface and steam. The

lower the pressure, the easier the molecules leaving the water surface and thus

less energy is required to achieve the state of equilibrium (boiling point). The

temperature where equilibrium occurs at a given pressure level is called saturated

temperature. The pressure where equilibrium occurs at a given temperature is

called saturated pressure. Marcet Boiler is used to investigate the relationship

between the pressure and temperature of saturated steam in equilibrium with water

at all temperature levels between the atmospheric pressure and 10 bars. The

measured value of the slope of the graph (dT/dP) obtained from the experiment

results can be compared to the theoretical value determined through calculation

from the steam table. Clausius-Clapeyron states:

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 (dTdP

)SAT

= T v fg

h fg

 (dTdP

)SAT

= T (v f−v g)hf−hg

Where, h f+hg=hg

Hence, h fg=¿ hg−hf ¿

As, vg≫v f

( dTdP

)SAT

= T (v f−v g)

hfg

=T vg

h fg

Where, v f=specific volumeof saturated liquid h fg=latent heat of vaporization

vg=specific volumeof saturated vapour

h f=enthalpy of saturated liquid

hg=enthalpy of saturated vapour

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4.0 DIAGRAM AND DESCRIPTION OF THE APPARATUS

The unit consists of a stainless steel pressure vessel fitted with high-pressure

immersion electric heater. The unit also comes with a safety relief valve,

temperature and pressure measuring devices. Water feed port is installed to allow

water charging. The unit also includes temperature and pressure transducer, so

that it is easy to read the respective valves on the digital indicator. The water heater

is protected from burnout by setting the maximum operating temperature with

temperature controller.

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5.0 EXPERIMENTAL PROCEDURE

1. A quick inspection is performed before starting the experiment to ensure the units

is in proper operating condition.

2. The Marcet boiler is connected to the nearest power supply.

3. The valves at the feed port are now opened.

4.The boiler is filled with distilled water at about half of  boiler’s height  through the f

feed port.

5. The valve at the level sight tube is then closed.

6 The power supply is then turned on, to start the experiment.

7. The temperature controller is set to 185.0o c, that is slightly above the expected

boiling point of water at 10bars (abs).

8. The valve at the feed port was opened while the heater was turned on.

9. The valve at the level sight tube are made sure to be closed before turning on the

heater as the sight tube is not designed to with stand high pressure

and temperature.

10.The rise of the steam temperature could be observed when the water boils.

11.The steam from the valve was allowed to come out for 30 seconds before the

valve was closed (this step is very important to remove the air from the boiler as

the accuracy of the experiment results would be significantly affected if air is

present)

12.The steam temperature, gauze pressure at 1.00bar (abs) and time taken for

steam to reach until 10.00bar (abs) is recorded.

13.After the experiment, the heater is allowed to cool down to room temperature.

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14.The time taken for the heater or boiler to cool down is also recorded.

15.All the readings of result are recorded and tabulated.

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6.0 RESULTS

Pressure,P(bar)

Tempreture,T Measured Slope,dT/dP

Calculated Slope,Tvg/h fggauge absolute Increase

(°C)Decrease

(°C)AverageT avc (°C)

AverageT avc (K)

0.00 1.0 0 0 0 0 0 00.10 1.1 105.2 106.8 106.00 379.00 37.9 0.2330.20 1.2 107.3 109.5 108.40 381.40 24.0 0.2180.30 1.3 109.8 111.8 110.80 383.80 24.0 0.2040.40 1.4 112.1 114.2 113.15 386.15 23.5 0.1910.50 1.5 114.4 116.1 115.25 388.25 21.0 0.1800.60 1.6 116.3 118.2 117.25 390.25 20.0 0.1710.70 1.7 118.2 120.1 119.15 392.15 19.0 0.1630.80 1.8 120.0 121.9 120.95 393.95 18.0 0.1560.90 1.9 121.9 123.6 122.75 395.75 18.0 0.1491.0 2.0 123.6 125.2 124.50 397.50 17.5 0.1421.1 2.1 125.2 126.8 126.00 399.00 15.0 0.1371.2 2.2 127.7 128.2 127.45 400.45 14.5 0.1321.3 2.3 128.2 129.8 129.00 402.00 15.5 0.1271.4 2.4 129.6 131.3 130.45 403.45 14.5 0.1231.5 2.5 131.2 132.6 131.90 404.90 14.5 0.1191.6 2.6 132.5 133.9 133.20 406.20 13.0 0.1151.7 2.7 133.8 135.1 134.45 407.45 12.5 0.1111.8 2.8 134.9 136.3 135.60 408.60 11.5 0.1091.9 2.9 136.3 137.7 137.00 410.00 14.0 0.1052.0 3.0 137.4 138.8 138.10 411.10 11.0 0.1032.5 3.5 143.0 144.1 143.55 416.55 10.9 0.0913.0 4.0 147.8 148.9 148.35 421.35 9.6 0.0823.5 4.5 152.3 153.3 152.80 425.80 8.9 0.0744.0 5.0 156.2 157.2 156.70 429.70 7.8 0.0684.5 5.5 159.8 160.8 160.30 433.30 7.2 0.0635.0 6.0 163.3 164.3 163.80 436.80 7.0 0.0595.5 6.5 166.5 167.4 166.95 439.95 6.3 0.0566.0 7.0 169.5 170.4 169.95 442.95 6.0 0.0536.5 7.5 172.2 173.2 172.70 445.70 5.5 0.0507.0 8.0 175.0 175.9 175.45 448.45 5.5 0.0477.5 8.5 177.5 178.3 177.90 450.90 4.9 0.0458.0 9.0 180.0 180.8 180.40 453.40 5.0 0.0438.5 9.5 182.3 183.2 182.75 455.75 4.7 0.0429.0 10 184.6 184.6 184.60 457.60 3.7 0.040

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7.0 SAMPLE CALCULATIONS

At T = 106.0 °C

Temperature, °C 105 106 110

vg, m3/kg 1.4186 vg 1.2094

106−105110−105

=vg−1.4186

1.2091−1.4186

vg = 1.37676 m3/kg

Temperature, °C 105 106 110

h fg, kJ /kg 2243.1 h fg 2229.7

106−105110−105

=h fg−2243.1

2229.7−2243.1

h fg=2240.42kJ /kg

Tvg = (379K)( 1.37676 m3/kg)

= 521.792 K.m3/kg

T v g

hfg

= 521.792K .m3/kg2240.42kJ /kg

= 0.233 K.m3/kJ

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Graph of dT/dPvs P and Tvfg/hfg vs P

dT/dP Tvfg/hfg

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1 2 3 4 5 6 7 8 9 100

50

100

150

200

250

300

350

400

450

500

Temperature Vs Pressure

1 2 3 4 5 6 7 8 9 100

2

4

6

8

10

12

14

16

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8.0 DISCUSSION

Marcet boiler was made by Nathan Chamberlain, Boston, USA, in the year1850.

He made this boiler for measuring the vapor pressure of saturated liquid. Later this

Marcet boiler was used to study the evaporation filtration of water. Pressure and

temperature are two fundamental quantities of materials in thermodynamics. These two

factors have relation directly proportional to each other.

When a container contains saturated liquid and are heated to it’s boiling

temperature, the liquid will be changing it’s state from liquid to steam. If the steam

are not allowed to escape from the container, their internal pressure will increase.

Because, when the liquid becomes gas by heating, the internal molecular energy will

increase and the atoms will be more excited. All the excited atoms will hit each other

and split with more speed or velocities. As their mass remains constant, so their forces

on each other will increases. And when their forces on them increases, an dare not

allowed to occupy more area, they exerts pressure on the container, which gradually

increases with temperature. Hence it is calculated and proved from the graph, that

temperature is directly proportional to the pressure. The error percentage should not

cross or exceed 10%, as the experiment was done in enclosed surface and no volume

of experimenting samples are allowed to escape from the system. That is done

in closed system. It is important to remove gas at the beginning to avoid the flaws of

reading due to pressure difference. Marcet boiler is being used as water boiler, gasifier,

power plant, cooking utensils, steam plant industries, etc.

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9.0 CONCLUSION AND RECCOMENDATIONS

From the experiment, it is found from the graph and calculation,temperature of a

saturated steam is directly proportional to the pressure in equilibrium with water. The

percentage error on the experiment for first two values were found higher than those

third value and onward. This happened due to take improper reading from the pressure

gauze and some technical fault. The rest of the result for percentage error are found “O”

zero percent, which is also not practically possible.

This happened due to taking the two figure after decimal, which reduce the

contrast of the reading. Disgracing some negligible faults, this experiment can be

consider successful, to improve the result of the experiment, it should be carried out at

room temperature switching off all the air-conditions, and also by repeating the

experiment and taking the average value. If some insulation were kept on the Marcet

boiler to reduce heat loss, the experiment could be more accurate.

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10.0 REFERENCES

1.CENGEL BOLES,THERMODYNAMICS: AN ENGINEERING APPROACH Seventh

Edition :McGraw-Hill:pg 910.

2.Jane MarcetConversations on chemistry [by J. Marcet]. By mrs.Marcet - Page 163

3. Sir William CrookesThe Chemical News and Journal of Industrial Science; with which

is Volumes 29-30 - Page 30

4.Digby Alfred WranghamThe Theory & Practice of Heat Engines - Page 139

5. Andrew JamiesonElementary Manual on Steam and the Steam Engine: Specially

Page 97

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