1. Cleaning the setup: Firstly clean the setup and fill your setup with distilled water.
2. Temperature set: Set the temperature of steam generator up to 400 K.
3. Maintain the pressure: Now slowly open the needle valve, maintain the constant gauge pressure.
4. Steady state is reached: When steady state is reached note the pressure difference from manometer and Temperature after throttling by thermometer.
5. Collecting the moisture: Collect the suspended moisture from the separating and throttling calorimeter then Weigh it.
6. Now at last calculate the dryness factor by the given formulae.
1 Water supply continuous for heat exchanger.
2 Space required: 1.0mx1.0 meter
3 Electricity supply: Single phase 220 V AC and 4 KW
4 Electronic balance say 1 kg
5 Steam table for calculation.
Term dryness factor refers to wet steam. It is defined as ration of mass of dry steam actually present to the mass of wet steam, which contains it.
Let in sample of wet steam
X= Dryness factor of sample,
Wd =Weigh of dry steam in kg
W=Weigh of water vapour in suspension
Separating and Throttling Calorimeter
The steam passing out from a separating calorimeter may still contain some vapours in it. In others words it may not absolutely dry. Again in a throttling calorimeter steam after passing through throttle valve must be superheated or at least dry saturated. This limits the extent of dryness factor. It can be reliably measured, depend on the pressure of the steam in the main steam pipe. If sample of steam which may still wet after passing through the throttle valve i.e. it will not be superheated. To overcome the difficulties we make use of combined separating and throttling. First steam is passed through separating calorimeter where it loses most part of the it’s moisture and become comparatively drier. It is then passed through the throttling calorimeter where superheating takes place without change of total heat. The temperature and pressure of the steam after throttling are measured by using a thermometer and manometer separately.
The setup consist of separating and throttling calorimeter. A steam generator is provided at the base of apparatus. A digital temperature controller provided to control the temperature inside the steam generator. Steam from the generator passed from separating calorimeter where most of the water particle gets separated from steam and then passed from separating calorimeter where most of the water particles gets separated from steam and then passed to throttling calorimeter where steam gets superheated. After that superheated steam passed through exchanger to condense the steam. A manometer and thermometer are connected with throttling calorimeter to measure the pressure and temperature after throttling process.