Page 195 - The Jet Engine

Water injection

sensing unit to each fuel spray nozzle and is sprayed compressor delivery air pressure and water
from two jets onto the flame tube swirl vanes, thus pressure. The system is brought into operation when
cooling the air passing into the combustion zone. The the engine throttle lever is moved to the take-off
water pressure between the sensing unit and the position, causing microswitches to operate and
discharge jets is sensed by the fuel control system, select the air supply for the turbine pump.
which automatically resets the engine speed
governor to give a higher maximum engine speed. 9. The sensing unit also forms a non-return valve to
prevent air pressure feeding back from the discharge
8. The water flow sensing unit opens only when the jets and provides for the operation of an indicator
correct pressure difference is obtained between light to show when water is flowing.

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