An injection apparatus for introducing a slurry of water-swellable gelling agent into a water line feeding a fixed fire-extinguishing system to form an ablative extinguishant therein. The apparatus includes a peristaltic pump driven by a hydraulic motor using water at line pressure for motive fluid and controlled by a servomechanism driven in part by a flow sensor to ensure injection rates corresponding to flow rates of water in the line. The injection apparatus is operated in a no-injection failure mode to avoid interference with normal flow of plain water to the fire-extinguishing system.
Method for continuously preparing a gel in which a liquid is mixed with a gelling agent in a hose or other conduit which serves to deliver the gel to the site at which it is used. The liquid and the gelling agent are supplied to the conduit in the proper proportions so that the gel is formed or completed approximate the output end of the conduit. The invention also includes apparatus for carrying out the specified method.
A portable fire extinguisher contains a supply of water and a gel forming chemical to be expelled under pressure through a mixing device contained in a small space by arranging a channel to follow a tortuous course, with an inlet for water and chemical at one end of the channel and further inlets for water at successive locations along the channel.
A fluid mixer for mixing a carrier liquid such as water with a thickening agent such as a liquid polymer employs a mixing apparatus in the form of an elbow pipe interconnecting the carrier liquid inlet with a discharge pipe. The polymer thickener is introduced into the fluid stream of the carrier liquid at a point on the outer radius of the elbow where the high velocity stream of carrier liquid impinges upon the side of the elbow pipe to cause the thickener to be impinged upon by the carrier stream at the point of its highest velocity to impart maximum hydraulic shear to the thickener liquid, insuring optimum mixing of the two liquids in the discharge pipe.
