Chapter 18, Problem 6P

Design of a community biogas plant for a village  consisting of 114 families, each family consisting of 5 persons (adults). Two children are equivalent to one person. Village survey report gives the following information’s about cattle’s Cows 185 (10 kg/day);       Oxes 135 (12 kg/day);     Buffalo 75 (15 kg/day)  ; pig 10 ( 3 kg/day); Gas produced from 1 kg of gobar in winter and summer 42 litre and 55 litre. Gas required for cooking/person/day = 0.227 m3 ,Gas required for lighting 100 cp lamp per hour = 0.126 m3 Each family is allotted 2 lamps, which would burn 3 hours daily, Density of slurry 1090 kg/m3 and retention time 35days.  Design the following parameters (i) gas required for cooking& Lighting (ii) Diameter of digester    Diameter d=

Calculate the specific energy of 13 m3/s of water flowing with a velocity of 1.5 m/s in a rectangular channel 7.5 m wide. Find the depth of water in the channel when the specific energy would be minimum. What would be the value of critical velocity as well as minimum specific energy?

2. Consider the system described in the news: at night, when there is energy left, water is pumped from a large lake to a reservoir at 80 m above the lake level. During the day, this water is used to generate energy in a turbine located 80 m below the elevated reservoir. Considering that the water flow is always 5000 liters/s (both at the inlet of the reservoir and at the outlet) and that the pump and turbine efficiencies are 70%, what is the power (in kW) required by the pump and the power (in kW) recovered in the turbine. Data: The pipe diameter is always the same along the system (d = 0.5 m); g = 10 m/s2; γ = 9810 N/m3. Matter transport phenomena; Please make it typeable as handwriting interferes with understanding