Thermodynamics
Objective: to show the relationship between pressure and temperature of saturated steam
Apparatus: a Marcet boiler (Figure 1) is used. It is provided with a pressure gauge, a digital thermometer and a safety valve. An aneroid barometer is used to determine atmospheric pressure.
1 2 3 Drain valve Heater Overflow
Variation of saturation temperature with pressure
Thermodynamics Laboratory Manual
Marcet boiler
4 5
6 7 8 9
Temperature sensor Pressure relief valve Filler opening with plug Pressure gauge Master switch Boiler with insulating jacket
11 Temperature display
10 Heater switch
The drain valve (1) can be used to drain the vessel. An electric heater (2) is bolted into the floor of the boiler in such a way that the heating element protrudes from below into the boiler. A pressure gauge (8) is fitted to provide a direct indication of the boiler pressure. There is also a Pt-100 temperature sensor (4) to measure the boiler temperature, and a safety valve (5) to prevent excess pressure build-up in the boiler. If the Safety valve is activated, the excess pressure is discharged to the rear of the unit via a drain pipe. The boiler temperature can be read from the digital display (11) fitted into the switch box. The unit is switched on at the master switch (9). The additional
8 Thermo_Lab_Manual_BE_Year_2_r008.docx
The main element of the apparatus is the stainless steel steam boiler (7). It has a mineral wool insulating jacket. The filler opening (6) is used to pour water into the boiler. The overflow valve (3), closed off by means of a knob, is used to ensure the vessel is filled to the correct level.
Figure 1 Marcet boiler apparatus (from Gunt AG manual, model WL204)
Procedure: The boiler must be filled before the unit is run for the first time. Subsequently the level should be checked routinely after a certain number of experiments have been performed Bring the water to its boiling point with the overflow valve opened. When
Apparatus: a Marcet boiler (Figure 1) is used. It is provided with a pressure gauge, a digital thermometer and a safety valve. An aneroid barometer is used to determine atmospheric pressure.
1 2 3 Drain valve Heater Overflow
Variation of saturation temperature with pressure
Thermodynamics Laboratory Manual
Marcet boiler
4 5
6 7 8 9
Temperature sensor Pressure relief valve Filler opening with plug Pressure gauge Master switch Boiler with insulating jacket
11 Temperature display
10 Heater switch
The drain valve (1) can be used to drain the vessel. An electric heater (2) is bolted into the floor of the boiler in such a way that the heating element protrudes from below into the boiler. A pressure gauge (8) is fitted to provide a direct indication of the boiler pressure. There is also a Pt-100 temperature sensor (4) to measure the boiler temperature, and a safety valve (5) to prevent excess pressure build-up in the boiler. If the Safety valve is activated, the excess pressure is discharged to the rear of the unit via a drain pipe. The boiler temperature can be read from the digital display (11) fitted into the switch box. The unit is switched on at the master switch (9). The additional
8 Thermo_Lab_Manual_BE_Year_2_r008.docx
The main element of the apparatus is the stainless steel steam boiler (7). It has a mineral wool insulating jacket. The filler opening (6) is used to pour water into the boiler. The overflow valve (3), closed off by means of a knob, is used to ensure the vessel is filled to the correct level.
Figure 1 Marcet boiler apparatus (from Gunt AG manual, model WL204)
Procedure: The boiler must be filled before the unit is run for the first time. Subsequently the level should be checked routinely after a certain number of experiments have been performed Bring the water to its boiling point with the overflow valve opened. When