Answer the attached problems. One paragraph for each question is enough. Document Preview: Sketch a schematic drawing of a pneumatic sewage ejector system. Describe the situations pr circumstances...

1. Sketch a schematic drawing of a system. Describe the situations or circumstances where a
pneumatic ejector station might be used. Discuss the unusual operating characteristics of a
pneumatic ejector station as compare to an electrically (motor) driven duplex pumping system.
Solution
Pneumatic ejector station is used if there is network of collection lines resembling a large stream fed by
many tributaries. Then this kind of ejector system is very useful.
The Pneumatic Ejector is unique as a pumping mechanism because no mechanical parts are involved in
the actual pumping of the material hence if it is blocked due to some blockage then we cannot use any
mechanical instruments to clear its blockage except doing it manually whereas in case of electrically
driven motor it can be done easily with pressure build up from outside machine or the system already
inbuilt in the sewage.
2. Why do engineers typically select larger peaking factors (PF) for water booster pumping stations
than for sewage pumping stations?
Solution
Peaking factors decides the design flow rate of a distribution system. Higher peaking factor is
esponsible for design maximum flow rate while lower peaking factor is responsible for design minimum
flow rate. Design maximum flow rate is chosen when there is flow of liquid which involves no solids
while lower design minimum flow rate is chosen when solids are also involved with liquid for better
cleansing of the pipe. Hence higher flow rate is always chosen for water booster pumps because only
water has to be passed through the pipe than sewage pumping station which contains solids as well.




3. Why does it take longer to fill a hydro pneumatic water tank than to empty the tank when the
system is in operation?
Solution...