Kidde IP Holdings Limited

Kidde IP Holding Limited

Robert James Lade

Robert G Dunster

Max D Allsworth

Brian David Powell

Simon James Davies

Peter O Jensen

Parviz James Monem

Thomas Dahl Andersen

Simon Davies

Robert George Dunster

Max Daniel Allsworth

David John Probyn

A fire and explosion suppression system comprises a source () of high pressure water which is fed to a misting nozzle () at one input of a mixing unit (), and a source () of high pressure inert gas, such as nitrogen, which is fed along a pipe () to another input of the mixing unit (). Inside the mixing unit (), water mist, in the form of an atomized mist of very small droplet size is mixed with the pressurized gas and exits the mixing unit () at high pressure and high velocity along a pipe () and is thence discharged through spreaders (). The source () of the water is pressurized by a feed () from the source of pressurized inert gas. The mass flow rate of the water will therefore reduce as the pressure of the gas decays. This tends to maintain the ratio of the mass flow rate of the water to the mass flow rate of the gas constant. This is found to produce and maintain an advantageous distribution of droplet size in the discharged unit. A control unit () adjusts a metering valve () in dependence on the mass flow rate or the pressure of the gas in order to adjust the ratio as necessary to maintain its value constant.

Fire and explosion suppression

A water and inert gas fire suppression system (), and method for extinguishing a fire in a protected space are provided with a simple and inexpensive freeze protection mechanism. To prevent the water, or other liquid fire extinguishing agent, entrained in the inert gas flow from freezing during transport through the inert gas distribution network () a secondary liquid is introduced into the inert gas flow and then removed from the inert gas flow upstream of the discharge of the two-phase water and inert gas flow into the space being protected. The inert gas is heated by means of the thermal inertia (TI) of the secondary liquid, which may be excess amount of water or an amount of another liquid having a thermal inertia (TI) at least equal to that of water.

Fire suppression system with freeze protection

A system for discharging inert gas for extinguishing or suppressing a fire is disclosed. A fluid discharge control arrangement is positioned in a fluid flow path between a pressurised gas supplyA,B,C and the target fire suppression zone. The fluid discharge control arrangement reduces the pressure in the fluid flow path downstream thereof. This may allow the downstream pipework to be selected to withstand a lower pressure than in a conventional system in which the fluid discharge control device was not provided, thereby reducing costs. The fluid discharge control device may comprise a first valveand first restrictorin the first flow pathand a second valveand a second restrictorprovided in the second flow path. Fluid from the containersA,B,C flows initially through flow pathand restrictor. Subsequently flow pathmay be closed by optional valve, and flow pathis opened by valve. Fluid flow then passes through restrictor. This reduces the peak pressure in the downstream pipework. In another embodiment the discharge of inert gas from the containersA,B andC is staggered to reduce the peak pressure in pipeline. A further embodiment provides a restrictor in the inletA,B,C from each of the containersA,B,C to the manifold, thereby also reducing the peak pressure in the pipeline

Fire suppression system

In use of a UV gas discharge tube (such as used in flame monitoring apparatus), an electric field is periodically applied in the tube, each application of the field being followed by an 'off' period in which the field is removed. During this process, the mean value of the statistical lag Tis measured over a predetermined time duration (the statistical lag is the time lag after each application of the electric field to the tube before conduction (if any) takes place). If the statistical lag lies within region I, the flame is judged to be present. If the statistical lag lies in region II, the flame is judged to be off (and a warning may be signalled). If the statistical lag lies in region III, a fault in the tube is signalled. This may be a 'field emission' fault whereby free electrons are generated by the applied electric field, without the presence of UV radiation or it may be a 'multiple counting' fault. Here, contamination of the gas within the tube causes the time required to de-ionise the gas, when the electric field is removed, to be increased. A multiple counting fault may be confirmed by monitoring each conduction of the tube and checking whether there is an immediately following conduction. A multiple counting fault may also be checked by increasing the lengths of the 'off' periods of the electric field and checking whether the mean statistical lag increases. The use of a supplementary light source is also disclosed which periodically illuminates the tube to check whether it has become room-light sensitive&#x2014;that is, sensitive to normal ambient light.

UV gas discharge tubes

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Marlow, United Kingdom

Robert James Lade