In: Mechanical Engineering
In a surface condenser a section of the tubes near to
the air pump suction is
screened off so that the air is cooled to a temperature below that
of the condensate, separate extraction
pumps being provided to deal with air and condensate respectively.
5448 kg of steam are condensed
per hour and the air leakage is 4.54 kg/h. The temperature of the
exhaust steam is 31°C, the temperature
of the condensate is 27°C, and the temperature at the air pump
suction is 21.1°C. Assuming a constant
vacuum throughout the condenser, find
() The mass of steam condensed per hour in the air cooler;
(i) The volume of air in m3/h to be dealt with by the air
pump;
(ii) The percentage reduction in necessary air pump capacity
following the cooling of the air..