Fire sprinkler system having combined detection and distribution piping

An air sampling fire sprinkler assembly for discharging a fire extinguishing liquid, comprising:

• a nozzle head comprising:
• a discharge conduit extending therethrough between an inlet end fluidly connectable to a pipe adapted to contain the fire extinguishing liquid and a discharging end;
• and
• a cavity having a first opening fluidly connected to the discharge conduit for receiving the fire extinguishing liquid therein and a second opening fluidly connected to the discharging end for receiving air therein, the second opening providing an air sampling port through which ambient air is drawn and adapted to be fed to an air sampling detector for testing the ambient air to detect the presence of a fire condition;
• a heat-sensitive device substantially hermetically sealing the discharge conduit of the nozzle head and adapted to unseal the discharge conduit at a predetermined temperature to discharge the fire extinguishing liquid;
• and
• a closure device positioned within the cavity and movable between a biased open position in which the closure device is spaced apart from the second opening and a closed position in which the closure device seals the second opening, a flow of the fire extinguishing liquid within the cavity allowing the closure device to move from the biased open position to the closed position.

A fire sprinkler system in communication with a source of fire extinguishing fluid, the fire sprinkler system comprising:

• a piping system having at least one dual-use pipe providing both an air conveying opening and a fire extinguishing fluid conveying outlet, the dual-use pipe having at least one air opening;
• a blower fluidly connected to the pipe to provide a substantially continuous flow of ambient air through the pipe, the ambient air entering or exiting the pipe via the at least one air opening;
• a control unit fluidly connected to the pipe to measure the flow of the ambient air therethrough, the control unit operable to detect a difference between a measured flow rate value of the ambient air through the pipe and a baseline flow rate value of the ambient air, a fire condition being detected by the control unit when a difference between the baseline flow rate and the measured flow rate exceeds a predetermined delta value;
• a valve disposed between the source of the fire extinguishing fluid and the pipe at the fluid conveying outlet, the valve being in communication with the control unit and operable to displace between an open position to fill the pipe with the fire extinguishing fluid upon detection of the fire condition, and a closed position;
• and
• at least one automatic sprinkler fluidly connected to the pipe for ejecting the fire extinguishing fluid from the pipe upon detection of the fire condition, said automatic sprinkler having a frangible component, the frangible component breaking to eject the fire extinguishing fluid from said automatic sprinkler upon an increase in temperature of the ambient air being indicative of the fire condition.

A method of suppressing fire with a fire extinguishing fluid, comprising:

• conveying ambient air through at least one dual-use pipe having at least one air opening and at least one fire sprinkler fluidly connected to the pipe, the ambient air entering or exiting the pipe via the at least one air opening;
• measuring a flow of the ambient air through the pipe to obtain a measured flow rate value of the ambient air;
• determining a difference between the measured flow rate value and a baseline flow rate value;
• and
• filling the pipe with the fire extinguishing fluid and expelling the fire extinguishing fluid from the at least one fire sprinkler when the difference between the measured and baseline flow rate values exceeds a predetermined delta value.