FIELD: mixing systems; firefighting.
SUBSTANCE: group of inventions relates to a mixing system (1) for fire extinguishing installations for creating a mixture of an extinguishing agent and an additive to an extinguishing agent (premix) by mixing an additive to an extinguishing agent, in particular a foam concentrate, to an extinguishing agent, in particular water, and also a group of inventions relates to method of operation of the mixing system. At the same time, the mixing system (1) has an engine driven by the flow of the extinguishing agent, a mixing pump (6) connected to this engine for pumping the additive to the extinguishing agent, an inlet pipeline (35) of the additive to the extinguishing agent, an admixing pipeline (10) and an outlet pipeline (13) extinguishing agent additives from which the extinguishing agent additive is mixed into the extinguishing agent in the admixture line (10). According to the invention, the mixing pump (6) is a piston pump having several cylinders and at least two outlets (8a, 8b) connected to these cylinders. At least one first reversible outlet (8b) is hydraulically connected with the possibility of switching either to a return line (29) through which the extinguishing agent additive flows back to the mixing pump (6) or to the additive outlet line (13) to the extinguishing agent. When the extinguishing agent additive from the reversible outlet (8a, 8b) flows back to the mixing pump (6), it does not mix with the extinguishing agent in the mixing pipeline (10).
EFFECT: mixing ratio can be easily changed by switching.
18 cl, 1 dwg
