Bissoy.com
Doctors Medicines MCQs Q&A

Determine the height of the chimney to get net draught of 12mm if the total losses are 4mm. the temperature of air is 25oC and the temperature of chimney gases is 300oC. The mass of air used per kg of fuel used is 18kg. One kg of air occupies a volume of 0.7734m3 at normal temperature?

Determine the height of the chimney to get net draught of 12mm if the total losses are 4mm. the temperature of air is 25oC and the temperature of chimney gases is 300oC. The mass of air used per kg of fuel used is 18kg. One kg of air occupies a volume of 0.7734m3 at normal temperature? Correct Answer 29.93

Density of air at normal temperature = 1/0.7734 = 1.293Kg/m3 Density of air at 298K, ρa = 1.293 × 273/298 = 1.1845 Kg/m3 Density of gases at 573K, ρg = 1.293 × ((18+1)/18) × 273/573 = 0.65 Kg/m3 But, P = 12 + 4 = 16 mm of water P = H (ρa – ρg) 16 = H (1.1845 – 0.65) H = 29.93m

Related Questions

A draught of 15mm of water is produced by using a chimney of height 30m. The ambient air and flue gases are at 27oC and 300oC respectively. The coal burned on the grate contains 81% carbon, 5% moisture and remaining ash. Neglect the losses and assume values of burnt products equivalent to the volume of air supplied and for the complete combustion of fuel, find the percentage of excess of air supplied?
Determine the height of chimney above grate level. Where diameter of chimney is 1.75m and produces a draught of 1.8cms of water. Temperature of flue gases is 290oC. The flue gases formed per kg of fuel burnt are 23kg. Neglect the losses and assume atmospheric temperature as 20oC?
Determine the height of the chimney to produce a static draught of 22mm of water if the mean flue gas temperature in chimney is 290oC and ambient temperature in boiler house is 20oC. The gas constant for air is 29.26Kgm/Kgk and for chimney flue gas is 26.2 Kgfm/Kgk. Assume reading as 760mm of mercury?
The draught (in mm of water), for maximum discharge of flue gases through the chimney, is given by (where H = Height of the chimney in meters and T1 = Absolute temperature of air outside the chimney in K)
Draught produced by a tall chimney due to density difference between hot flue gas inside the Chimney and atmospheric air outside the chimney is more appropriately known as the __________ draught.
A chimney of height 45 m is full of hot gases at temperature 330°C. If the discharge through the chimney is maximum, determine the draught in terms of column of hot gases. The ambient is 25°C.
A 15kg of air is supplied per kg of fuel burnt to the combustion chamber of a boiler using fuel 600kg/hr. the temperature of flue gases and ambient air are 273°C and 32°C. If the minimum draught required to start the flue is 9.5mm of water, find out the minimum height of the chimney?
In wet soil mass, air occupies one-seventh of its volume and Water occupies one- eighth of its volume. What will be the ratio of volume of voids with respect to the total volume?
A lady wants to buy the following items in the given price range- 1. Tomato between Rs. 40 and Rs. 45 per kg. 2. Grapes in the price range of Rs. 80 and Rs. 90 per kg. 3. Milk packets at Rs. 23 per liter. In which shop from the following will she definitely get all her items/ A. Shop S sells tomato at Rs. 22.5 per half kg, Grapes at Rs. 82 per kg and milk at Rs. 24 per liter. B. Shop H sells grapes at Rs. 21 per quarter kg, milk at 12.5 per half litre and tomato at Rs. 22 per half kg. C. Shop O sells milk at Rs. 11.5 per half litre, tomato at 21 per half kg and grapes at Rs. 43 per half kg. D. Shop P sells tomato at Rs. 23.5 per half kg, grapes at Rs. 85 per kg and milk at Rs. 23 per litre.
What is the enthalpy change of a reaction at 45oC, if the enthalpy of reactant at 45oC and 25oC are 10 J and 6 J, and enthalpy of product at 45oC and 25oC are 15 J and 8 J, and the enthalpy change of reaction at 25oC is 10 J?