Orsat Gas Apparatus - Free download as Word Doc .doc), PDF File .pdf), Text File .txt) or read online for free. orsat. Aim: Determination of exhaust gas analysis by using Orsat apparatus. Apparatus: Orsat apparatus Theory:The combustion products are mainly gaseous. RESULT: Hence we studied the Orsat apparatus for analysis of flue gases. Determination of calorific value of a fuel by Bomb calorimeter. ➢ Flue gas analysis by ORSAT apparatus. ➢ Study of valve timing diagram of Diesel Engine.
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FLUE GAS ANALYSIS - ORSAT APPARATUS INTRODUCTION To have proper control on combustion Download ORSAT APPARATUS. To have proper control on combustion process, an idea about complete or complete combustion of fuel is made by the analysis of flue gas. Thus,. (i) if the gases. The Orsat apparatus is usually limited to the three common constituents of flue gases, and is not suitable for the analysis of a fuel gas. However, in Fig. 1 there is .
Orsat Gas Apparatus
Simple tests can be made; for example: If after the cock G is closed, the bottle F is placed on top of the frame for a short time and again brought to the zero mark, the level of the water in A is above the zero mark, a leak is indicated. Before taking a final sample for analysis, the burette A should be filled with gas and emptied once or twice, to make sure that all the apparatus is filled with the new gas.
The cock G is then closed and the cock I in the pipette B is opened and the gas driven over into B by raising the bottle F. The gas is drawn back into A by lowering F and when the solution in B has reached the mark in the capillary tube, the cock I is closed and a reading is taken on the burette, the level of the water in the bottle F being brought to the same level as the water in A.
The operation is repeated until a constant reading is obtained, the number of cubic centimeters being the percentage of CO 2 in the flue gases. The gas is then driven over into the pipette C and a similar operation is carried out.
The difference between the resulting reading and the first reading gives the percentage of oxygen in the flue gases. The next operation is to drive the gas into the pipette D, the gas being given a final wash in E, and then passed into the pipette C to neutralize any hydrochloric acid fumes which may have been given off by the cuprous chloride solution, which, especially if it be old, may give off such fumes, thus increasing the volume of the gases and making the reading on the burette less than the true amount.
The process must be carried out in the order named, as the pyrogallic solution will also absorb carbon dioxide, while the cuprous chloride solution will also absorb oxygen. As the pressure of the gases in the flue is less than the atmospheric pressure, they will not of themselves flow through the pipe connecting the flue to the apparatus.
The gas may be drawn into the pipe in the way already described for filling the apparatus, but this is a tedious method. For rapid work a rubber bulb aspirator connected to the air outlet of the cock G will enable a new supply of gas to be drawn into the pipe, the apparatus then being filled as already described.
Another form of aspirator draws the gas from the flue in a constant stream, thus insuring a fresh supply for each sample. The analysis made by the Orsat apparatus is volumetric; if the analysis by weight is required, it can be found from the volumetric analysis as follows: Multiply the percentages by volume by either the densities or the molecular weight of each gas, and divide the products by the sum of all the products; the quotients will be the percentages by weight.
For adjusting final volume, the three-way stop-cock is opened to atmosphere and the reservoir is carefully raised, till the level ofwater in it is the same as in the burette, which stands at mL mark.
The three-way stop-cock is then closed.
STEP 2 The stopper of the absorption bulb, containing caustic potash solution, is opened and all the gas is forced into this bulb by raising the water reservoir.
The gas is again sent to the burette.
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STEP 2 Contd.. The unabsorbed gas is finally taken back to the burette, till the level of solution in the CO2 absorption bulb stands at the constant mark and then, its stop-cock is closed. The levels of water in the burette and reservoir are equalised and the volume of residual gas is noted.
The decrease in volume-gives the volume of CO2 in mL of the flue gas sample.
STEP 3 The volumes of O2 and CO are similarly determined by passing the remaining gas through alkaline pyrogallic acid bulb and ammonical cuprous chloride bulb respectively. Then their respective valves are closed. All the air in the reservoir bottle is expelled to atmosphere by lifting the reservoir bottle and opening the three-way to atmosphere. The gas in the burette is expelled to the atmosphere to remove any air left in the joints, tubes, etc.
This procedure is repeated times to ensure a right sample of the gas taken for analysis. This is because the absorbent used for O2 i. The Orsat analysis of the flue gas shows For accurate work it is advisable to use four pipettes, B, C, D, E, the first containing a solution of caustic potash for the absorption of carbon dioxide, the second an alkaline solution of pyrogallic acid for the absorption of oxygen, and the remaining two an acid solution of cuprous chloride for absorbing the carbon monoxide.
The gas is then driven over into the pipette C and a similar operation is carried out. The gas is drawn back into A by lowering F and when the solution in B has reached the mark in the capillary tube, the cock I is closed and a reading is taken on the burette, the level of the water in the bottle F being brought to the same level as the water in A. This means that the sum of the partial pressures of the remaining constituents is constant.
Gas analysis apparatus Orsat-Fischer
I , gas enters by a rubber connection marked A , passing through a cotton filter shown, which is attached by tubing to a fitting, B, which takes any strain brought upon the connection.
The rear half of each pipette is fitted with a rubber bag, one of which is shown at K, to protect the solution from the action of the air. The reading on the measuring burette will be the sum of volume of CO2 and O2.