Leakproof draft system pressure/vacuum relief device for power plants

A gas ducting system capable of adapting to sudden positive or negative pressure changes in a duct carrying a flowing gas, said system comprising in combination:

• (a) a duct for carrying flowing gas;
• (b) at least a liquid reservoir containing a liquid, said reservoir including a divider element that divides the reservoir into a duct side and a vent side such that liquid or gas can pass under the divider element to move between the two sides of the reservoir;
• (c) a gas conduit that connects the duct at a connection location to a region above the duct side of the reservoir;
• and,
• (d) a stack conduit for carrying gas or liquid, said stack conduit extending generally vertically from the reservoir to above the top of the vent side of the reservoir, an upper end of the stack conduit being in fluid communication with the ambient atmosphere.

A method for alleviating pressure changes in a gas duct of a gas ducting system, said method comprising the steps of:

• (a) providing at least a liquid reservoir containing a liquid, said reservoir including a divider element that divides the reservoir into a duct side and a vent side such that liquid or gas can pass under the divider element to move between the two sides of the reservoir;
• (b) providing a stack conduit for carrying gas or liquid, said stack conduit extending generally vertically from the reservoir to above the top of the vent side of the reservoir, an upper end of the stack conduit being in fluid communication with the ambient atmosphere;
• (c) fluidically coupling said gas duct to a region above the duct side of the reservoir;
• and,
• (d) under elevated pressure conditions in the gas duct, flowing gas from the gas duct into the region above the duct side of the reservoir;
• or, alternatively, under reduced pressure conditions in the gas duct, flowing air from the ambient environment through the liquid reservoir and into the gas duct.