Injector device for an apparatus suitable for mixing chemically reactive components

Method for supplying a chemically reactive component to a mixing chamber of a mixing head and for presetting and regulating the pressure of the reactive component upstream of an injector device by a modular structure, included in said injector device and that is geometrically and functionally configured in an axisymmetric manner, said method including the steps of:

• a) providing a hollow body extending around a longitudinal symmetry axis and wherein there are obtained at least one supply opening and a nozzle orifice arranged for facing and communicating with said mixing chamber obtained in said mixing head,
• b) housing and guiding a partializing and control element slidable within said hollow body along said longitudinal symmetry axis, wherein said partializing element is configured with a pin shape and includes a tip or tang portion on which a flat circular edge is obtained that is configured to vary a narrowed active section of said nozzle orifice,
• c) conforming said hollow body with an inlet chamber for the reactive component, on which at least one said supply opening is obtained, and an accumulating conveying end chamber for the reactive component is obtained,
• d) interposing between said inlet chamber and said end conveying chamber a collar element with a turbulator function,
• e) conforming said partializing and control element with a connection portion and a tip end portion with a flat end circular edge conformed for receiving pressure from the respective polymeric component delivered into said hollow body so as to move away said partializing and control element from said nozzle orifice to vary the area of said narrowed active section,
• f) applying a modular adjusting and contrasting unit, in an axisymmetric configuration, which is removably couplable with said hollow body and with said partializing and control element, said modular adjusting and contrasting unit being configured to exert an axisymmetric thrust action on said partializing and control element, being suitable for setting up said partializing and control element in an initial position and preload condition so as to adjust said narrowed active section to a reference flowrate and pressure of the reactive component and, subsequently, to vary the position of said partializing and control element so as to adjust said narrowed active section as a function of the flowrate variation, exerting a contrasting force that is suitable for balancing the thrust exerted by the pressure of the polymeric component, maintaining the variations of the pressure within limited values,
• g) conforming said modular adjusting and contrasting unit, including a series of piled and interchangeable elastic elements of conical disc shape, to perform a contrasting elastic action so as to contain and limit the force variation arising from the retraction stroke of said partializing and control element, limiting the pressure variation as much as possible as the flowrate of the respective polymeric component entering said hollow housing and guide body varies,
• h) configuring said modular adjusting and contrasting unit, with said tip portion with said flat circular edge and said nozzle orifice so that they impart to said injector device an axisymmetric geometric conformation with a high section gain, corresponding to a high ratio between the variation of the area of the narrowed active section and the shift or variation of longitudinal position of said partializing and control element.