ABSTRACTThe purpose of this experiment was carried out to demonstrate the relationship between the pressure and temperature of saturated steam in equilibrium. Besides that, to demonstrate the vapor pressure curve. In this experiment, steam temperature was observed as the water boils rised. The steam temperature and pressure was recorded when the boiler was heated until the steam pressure reaches 10.0 bar (abs). The steam temperature was recorded when the boiler was cooled until the steam reached atmospheric pressure. From the graph shown, the relationship between temperature and pressure is directly proportional as the temperature increased, the pressure increased. From the table showed, the measured slope and calculated slope were decreased as the temperature increased. As a conclusion,the experiment was successful based on the theory even there were some error.

Table of contents

Abstract..................................................................................................................1Table of Contents...................................................................................................2

1.1 Introduction.....................................................................................................31.2 Objectives31.3 Theory..4-51.4 Diagram and Description of Apparatus6-81.5 General Operating Procedure8-91.6 Experimental Procedures.9-10

1.7 Results and Discussion11-131.8 Sample calculations.14-151.9 Conclusion and Recommendation...16-171.10 References..181.11 Appendices.18

1.1 INTRODUCTIONThe Marcet Boiler is designed to demonstrate the principal in thermodynamic studies which is the boiling phenomenon. At the temperature of 100C, the temperature of the water constant due to the amount of latent heat needed to break the bond between water particles. At this stage vapor and liquid are in the same ratio. The volume begins to change rapidly as the liquid is being transformed into vapor [3]. The process continued until the last drop of liquid vaporized this is called as saturated vapor [1]. The units help to study the relationship between the pressure and the temperature of saturated steam in equilibrium with water. The pressure increases with the increase of the boiler temperature this is due to the gas ideal law in equation (1).The boiling point of the water in this experiment is 100 C, this is due to the experiment that had been done in the atmospheric pressure. If the pressure is increase 2 atm, the water will start boiling at 200 C [1]. The steam was allowed to come out at valve V3 for at least 30 seconds before temperature was recorded. This step is important to remove air from the boiler as the accuracy of the experimental results will be significantly affected when air is present [2]. The increase of temperature was recorded from 1 to 10 bar of absolute pressure.

1.2 OBJECTIVESThe objective for this experiment is to demonstrate the relationship between the pressure and temperature of saturated steam in equilibrium and to demonstrate of vapor pressure curve. The temperature was recorded and determine at the pressure within 10 bar. The increases energy within water, increasing of activities among molecules which increase the number of molecules escaped from the surface.

1.3 THEORYThe Marcet Boiler was used to investigate the relationship between the pressure and temperature of the saturated steam in equilibrium with water at 1 bar to 10 bar of absolute pressure. An ideal gas can be divided to three states variables, they are absolute pressure (p), absolute temperature (T) and volume (V). The relationship between them had been deduced from the kinetic theory and becoming ideal gas law. The ideal gas law equation managed to predicts the P-v-T behavior of a gas accurately within some properly selected region. The simplest and best-known equation that involve gas phase is the ideal gas law.PV = nRT (1)Where,P = Absolute pressureV= volumen = amount of substances (moles)R = ideal gas constantT = absolute temperature (K)When a gas law behave exactly like a ideal gas law. It were predicted to behave in terms of volume, pressure and temperature, then the gas is said to be an ideal gas. If the gas are opposite from the ideal gas law, then the gas is said to behave like a real gas. The energy continuously supply to the boiler until it reach boiling point. The temperature increases as the activities among molecules also increases. The increase in temperature causes the bond between particles of water to break and the number of molecule escape from the surface also increase. The activities continue until an equilibrium states is reached. At lower pressure, less of energy is needed to achieve equilibrium states, which is less energy is required to achieve equilibrium states. The temperature where the equilibrium state achieved is known as saturated temperature.Clapeyron equation is to determine the enthalpy of vaporization hfg at a given temperature by simply measuring the slope of the saturation curve on a P-T diagram and the specific volume of saturated liquid and saturated vapor at the given temperature [2]. The measured value that is obtained from the gradient of the graph (dT/dP) SAT could be compared with the values calculated in data in steam tables. Clausius-Clapeyron equation:(SAT = SAT = And hf + hfg = hgHence, hfg = hg - hfSAT = = As Vg >> VfIn which :Vf= Specific volume of saturated liquidVg= Specific volume of saturated vaporhf= Enthalpy of saturated liquidhg= Enthalpy of saturated vaporhfg = Latent heat of vaporization

1.4 DIAGRAM AND DISCRIPTION OF APPARATUSThe unit used in the experiment consists of a stainless steel pressure vessel which equipped with high pressure immersion electrical heater. This unit also connected to a safety relief valve, temperature and pressure measuring devices and to allow the water, the feed port of water is installed. The unit consists of temperature and pressure transducers to get the reading of value easily on the digital indicators. The temperature is setting using a temperature controller to the maximum operating temperature.

21098765431Figure 1: Unit Construction for Marcet Boiler (Model: HE169)

1. Pressure Transducer2. Pressure Indicator 3. Temperature Controller/Indicator4. Control Panel5. Bench6. Bourdon Tube Pressure Gauge7. Temperature Sensor8. Pressure Relief Valve9. Heater10. Water Inlet Port & Valve

The Marcet Boiler (Model: HE 169) consists of mainly the following items:a) Pressure VesselCapacity : 3 LitersMaterial : Stainless Steel 304Design Pressure : 30 barOperating Pressure : 10 barCertification : DOSH certifiedb) Pressure GaugeType : Bourdon TubeRange : 0-20 bar (g)c) Pressure TransducerWetted Material : Stainless SteelCase Material : Stainless SteelRange : 0-16 bar (abs)d) Electrical HeaterPower : 2000WType : Immersion TypeSafety : High temperature cut-off by means of a temperature controller

e) Temperature SensorType : RTD (Class A)Range : 0-200 oCf) Safety FeaturesPressure Relief Valve (Set at 15 bar), Temperature Controller (Set at 185.0 oC)Experimental Capabilitiesa) Demonstration of relationship between the pressure and temperature of saturated steam in equilibrium with waterb) Demonstration of the vapor pressure curveOverall DimensionsHeight : 1.15 mWidth : 1.00 mDepth : 0.60 mGeneral RequirementsElectrical : 240 VAC/1-phs/50HzWater Supply : Distilled water

1.5 GENERAL OPERATING PROCEDURES1.0 General Start-up Procedures1. Make sure the unit was operated in conditioned properly and the unit was connected to the power supply.2. The valves at feed port and level sight tube were opened which are V1,V2 and V3.3. The boiler was filled with distilled water through the feed port and the water level has been determined at about the half of height of the boiler.4. At the level sight tube, the valves, V1 & V2 were closed back and turned on the power supply switch.5. The experiment was ready to be performed.

2.0 General Shut-down Procedures1. The heater was switched off and the temperature was allowed to drop until same as room temperature.2. The main switch and the main power supply were switched off.3. Water was retained for the subsequent use.4. The water was drained off by opened V3 at the upper part of the level sight tube and V1 and V2 were opened then.

Note: The water inlet port was highly pressurized at high temperature. Do not open the valve at the water inlet port.

1.6 EXPERIMENTAL PROCEDURE1. The general start-up procedures as mentioned in section 1.0 were implemented.2. When the water had been filled into the boiler, the valves at the level sight tube, V2 and V3 were then opened to check the water level. Distilled water can be added if needed then the valves ware closed back.3. The temperature controller was set up to 185.0 oC where was slightly above the expected boiling point of the water at absolute pressure, 10.0 bar.4. The vent valve, V3 was opened and the heater was turned on.5. The increased of steam temperature was observed as the water was boiled.6. Steam was allowed to come out for about 30 seconds from the valve, V3 and the valve was closed back. This is because the presence of air could be significantly affected to the accuracy of the experimental results.7. The steam temperature and pressure were observed and recorded while the boiler is heated until the pressure was reached at 10.0 bar (abs).8. The heater was turned off and then the temperature and pressure were started to descend. The steam temperature was recorded until the steam pressure reached at atmospheric pressure while the boiler was allowed to cool down at room temperature.9. The reading of steam temperatures at different pressure when the boiler is heated and cooled.Precautions:1. The valve at the water inlet port should not be opened as it is highly pressurized as the temperature increased when switched off the heater.2. Before the heater was turned on, the valves at the level sight tube must have been ensured to be closed due to the sight tube unable to withstand high pressure and temperature.3. While the boiler was heated, never open the valve as pressurized steam and it may cause serious injury.4. Do not touch any part of the boiler during it was heated at high temperature.5. Never closed near to the valve, V3 the place where the steam was allowed to release out because it may cause injury. 1.7 RESULT AND DISCUSSIONRESULTTable 1: Saturated temperature of water at different pressurePressure , P(bar)Temperature, T( C)Measured Slope,dT/dP

Calculated Slope, Tvg/hfg

GaugeAbsoluteIncrease( C)Decrease ( C)Average Tavg ( C)Average Tavg (K)

0.001.00102.0103.5102.75375.75-0.0700

0.101.10105.3106.7106.00379.000.3200.0651

0.201.20107.5109.4108.45381.450.2420.0600

0.301.30109.8111.9110.85383.850.2400.0587

0.401.40112.1113.9113.00386.000.2120.0562

0.501.50114.3116.2115.25388.250.2220.0535

0.601.60116.3118.2117.25390.250.1970.0515

0.701.70118.2120.1119.50392.500.2220.0491

0.801.80120.1122.1121.10394.100.1580.0476

0.901.90121.9123.8122.85395.850.1730.0460

1.002.00123.6125.2124.40397.400.1530.0445

1.102.10125.2126.9126.05399.050.1630.0431

1.202.20126.8128.6127.70400.700.1630.0418

1.302.30128.3130.0129.15402.150.1430.0406

1.402.40129.8131.5130.65403.650.1480.0395

1.502.50130.9132.8131.85404.850.1180.0386

1.602.60132.5133.9133.20406.200.1330.0377

1.702.70133.7135.3134.50407.500.1280.0367

1.802.80135.1136.4135.75408.750.1230.0360

1.902.90136.3137.7137.00410.000.1230.0351

2.003.00137.5138.8138.15411.150.1140.0344

2.503.50142.5144.2143.55416.550.1070.0311

3.004.00147.9149.0148.45421.450.0970.0286

3.504.50152.2153.3152.75425.750.0850.0266

4.005.00156.2157.2156.70429.700.0780.0249

4.505.50160.0160.9160.45433.450.0740.0233

5.006.00163.3164.3163.80436.800.0660.0223

5.506.50166.5167.4166.95439.950.0620.0211

6.007.00169.5170.4169.95442.950.0590.0201

6.507.50172.3173.2172.75445.750.0550.0192

7.008.00175.1175.9175.50448.500.0540.0184

7.508.50177.6178.5178.05451.050.0500.0178

8.009.00180.1180.8180.45453.450.0470.0171

8.509.50182.4183.2182.8455.800.0460.0166

9.0010.00184.6184.6184.6457.600.0360.0161

Figure 1.1: Graph of Temperature versus Pressure

Figure 1.2: Graph of dT/dP versus P and Tvfg/hfg

DISCUSSIONIn Marcet Boiler experiment, before the experiment begin, the air in the boiler must removed to get the accurate value. The result will affected if the air was presence in the boiler. The result was taking after the water in the boiler was boiled and the steam was out. Graph plotted from figure 1.1 shows that the relationship between temperature and pressure in absolute was increased. The temperature was increased when the pressure increase. Graph plotted from figure 1.2 shows that the relationship between measured slope and calculated slope versus pressure in absolute is inversely proportional. The slope was decreased when the pressure is increase. There are some sources of error of the experiment which is measurement, room temperature, pressure and calculation. During a vaporization process, a substances exits as a part of liquid and a part of vapor. The properties of the saturated liquid were same whether it exists alone or in a mixture with saturated vapor. The amount of saturated liquid was changed when process of vaporization happened but not its properties and also same with saturated vapor. When the liquid absorbed enough heat energy, it will change to vapour form where vapor carried out activities among the molecule that enable molecule to escape from the surface until vapor reached equilibrium. As the steam is not allowed to exit, it will cause an increase in pressure and thus causing the temperature to increase. Applications of Marcet Boiler in industry that include water boiler, gasifier, power plant and cooking utilities.

1.8 SAMPLE CALCULATIONFrom the data : Tavg (C) : : 108.45 C T avg (K) : 108.45 + 273 : 381.45 KMeasured Slope, at T1 = 381.45 K and T2 = 383.85 KdT = 383.85 K 381.45 K = 2.4 KAt P1 = 1.2 bar and P2 = 1.3 bardP = 1.3 bar 1.2 bar = 0.1 bar x x = 10 kPa = = 0.24Calculate measured slope , = , Calculate ,

Calculate ,

= 1.217768

Calculate ,

= 2210.94 Calculated slope, = = 0.06

1.9 CONCLUSION AND RECOMMENDATIONConclusionThe relationship between pressure and temperature of saturated steam is observed. The pressure and temperature were showed on the pressure indicator and temperature controller. To make the experiment`s result as efficient as possible, the Ideal Gas Equations and thermodynamics theory were used. Evaluate the slope from derivation of formula and used the data given from the steam table. Compared the calculated slope (Tvg/hfg) and measured slope (dT/dP) from the table and graphs. After analyzing the experimental and theoretical results, the experimental slope is similar to the theoretical slope which shows the accuracy of the test. The plotted graphs showed that the pressure is directly proportional to the temperature which is the relationship between temperature and pressure in absolute was increased. The temperature of saturated steam was increased when the pressure of saturated steam increase. It can be proved that the fluid used for the experiment was pure water because the fluid boils at 373K. As conclusion the experiment was successful even there were small possible errors in this experiment. To improve the accuracy of the result the experiment should be performed carefully and the instruction should be followed.

Recommendation1. Take pressure readings with lighty tapped.2. Remove the air from the Marcet boiler.3. Set the boiler at room temperature at the initial state.

1.10 REFERENCES[1] Yunus A. C. and Michael A. B., Thermodynamic, 6th ed., New York, NY: McGraw-Hill, pp. 114-115, 677 ,(2007).[2]. Laboratory Manual of Chemical Engineering. Marcet Boiler. University Teknologi Mara Pulau Pinang. [3] Edward E. A., Thermodynamic, 7th ed., United States of America, Henry N. Sawyer Company Inc. pp 99, 20 (1994)

1.11 APPENDICES

Saturated Water (H2O)--Temperature Table

Spec. VolumeInternal EnergyEnthalpyEntropy

deg-CkPam^3/kgkJ/kgkJ/kgkJ/kg*K

Temp.Sat.Sat.Sat.Sat.Sat.Sat.Sat.Sat.Sat.

press.liquidvaporliquidvaporliquidvaporliquidvapor

T0Cp_sat@Tvfvgufughfhgsfsg

0.010.61130.001000206.140.002375.30.002501.40.00009.1562

50.87210.001000147.1220.972382.320.982510.60.07619.0257

101.22760.001000106.3842.002389.242.012519.80.15108.9008

151.70510.00100177.9362.992396.162.992528.90.22458.7814

202.3390.00100257.7983.952402.983.962538.10.29668.6672

253.1690.00100343.36104.882409.8104.892547.20.36748.5580

304.2460.00100432.89125.782416.6125.792556.30.43698.4533

355.6280.00100625.22146.672423.4146.682565.30.50538.3531

407.3840.00100819.52167.562430.1167.572574.30.57258.2570

459.5930.00101015.26188.442436.8188.452583.20.63878.1648

5012.3490.00101212.03209.322443.5209.332592.10.70388.0763

5515.7580.0010159.568230.212450.1230.232600.90.76797.9913

6019.9400.0010177.671251.112456.6251.132609.60.83127.9096

6525.030.0010206.197272.022463.1272.062618.30.89357.8310

7031.190.0010235.042292.952469.6292.982626.80.95497.7553

7538.580.0010264.131313.902475.9313.932643.71.01557.6824

8047.390.0010293.407334.862482.2334.912635.31.07537.6122

8557.830.0010332.828355.842488.4355.902651.91.13437.5445

9070.140.0010362.361376.852494.5376.922660.11.19257.4791

9584.550.0010401.982397.882500.6397.962668.11.25007.4159

1000.101350.0010441.6729418.942506.5419.042676.11.30697.3549

1050.120820.0010481.4194440.022512.4440.152683.81.36307.2958

1100.143270.0010521.2102461.142518.1461.302691.51.41857.2387

1150.169060.0010561.0366482.302523.7482.482699.01.47347.1833

1200.198530.0010600.8919503.502529.3503.712706.31.52767.1296

1250.23210.0010650.7706524.742534.6524.992713.51.58137.0775

1300.27010.0010700.6685546.022539.9546.312720.51.63447.0269

1350.31300.0010750.5822567.352545.0567.692727.31.68706.9777

1400.36130.0010800.5089588.742550.0589.132733.91.73916.9299

1450.41540.0010850.4463610.182554.9610.632740.31.79076.8833

1500.47580.0010910.3928631.682559.5632.202746.51.84186.8379

1550.54310.0010960.3468653.242564.1653.842752.41.89256.7935

1600.61780.0011020.3071674.872568.4675.552758.11.94276.7502

1650.70050.0011080.2727696.562572.5697.342763.51.99256.7078

1700.79170.0011140.2428718.332576.5719.212768.72.04196.6663

1750.89200.0011210.2168740.172580.2741.172773.62.09096.6256

1801.00210.0011270.19405762.092583.7763.222778.22.13966.5857

1851.12270.0011340.17409784.102587.0785.372782.42.18796.5465

1901.25440.0011410.15654806.192590.0807.622786.42.23596.5079

1951.39780.0011490.14105828.372592.8829.982790.02.28356.4698

2001.55380.0011570.12736850.652595.3852.452793.22.33096.4323

Figure 1 : Temperature table for saturated water

13