Safety device for seal systems for propeller shafts on ships

A ship comprising:

• a hull;
• said hull comprising:
• a bow;
• a stern;
• a length extending from said bow to said stern;
• first and second sides extending from said bow to said stern;
• and
• a width between said first and second sides;
• an engine disposed within said hull;
• a rotary propeller shaft driven by said engine;
• a seal system to seal said rotary propeller shaft against the outside water;
• said seal system defining an annular space around said rotary propeller shaft;
• a discharge line for the discharge of liquids from said annular space;
• a gas pressure source for receiving a gas under pressure;
• means for receiving a gaseous pressure medium into said annular space;
• said means for receiving comprising a feed line for supplying the gas from said gas pressure source;
• and
• a safety device comprising:
• sensing means for sensing the accumulation of liquids in said feed line;
• and
• a valve in said feed line, controlled by said sensing means, to close said feed line.

A safety device for a ship propeller seal comprising:

• a pressure source for a gas under pressure;
• means for delivering a gaseous pressure medium to an annular region of a ship propeller seal;
• said means for delivering comprising a feed line for supplying the gas from said gas pressure source to an annular region of a ship propeller seal;
• sensing means for sensing an accumulation of liquids in a gas feed line and generating a signal upon sensing an accumulation of liquids in said feed line;
• and
• a valve in said feed line, controlled by said sensing means, to close said feed line.