Questions

14.6 Flash Steam

1 What is the difference between live steam and flash steam?
a) Live steam is made from water, flash steam is made from condensate
b) Live steam is always hotter than flash steam
c) Live steam is made by adding heat to water, flash steam is made from heat already contained in water
d) Live steam is always at a higher pressure than flash steam
2 What percentage of flash steam is made from condensate at 10 bar g passing into a flash vessel at 0.5 bar g?
a) 12%
b) 13%
c) 14%
d) 5%
3 What is the effect on the production of flash steam from sub-saturated condensate?
a) The flash steam produced is less than that with saturated condensate
b) The flash steam produced is more than that with saturated condensate
c) There is no effect at all
d) Live steam is always at a higher pressure than flash steam
4 With reference to Example 14.6.1, what would be the proportion of flash steam produced if the flash pressure were 2.5 bar g?
a) 3%
b) 6%
c) 8%
d) 10%
5 In a steam system, the trap pressure is 15 bar g, the flash pressure is 0.5 bar g, and the condensate flowrate is 1300 kg/h. Which flash vessel is required?
a) FV6
b) FV8
c) FV12
d) FV16
6 What is used to top-up the flash pressure?
a) A safety valve
b) A larger condensate flow
c) A pressure surplussing valve
d) A pressure reducing valve