Multi-row coaxial melt-blown system

A multi-row coaxial melt-blown system comprising:

• a support including one or more first ducts configured to convey polymeric fluid parallel to a delivery direction and at least a second duct configured to convey air or gas,
• a box removably constrained to said support and including:
• a plurality of acceleration ducts extending parallel to said delivery direction comprising tubes in fluid passage connection with said one or more first ducts and configured to distribute said polymeric fluid,
• first holes extending parallel to said delivery direction, centred and spaced with respect to said acceleration ducts along said delivery direction and configured to house each part of a respective said tube,
• second holes extending parallel to said delivery direction action and adapted to allow the passage of air or gas, and
• a slit extending transversely to said delivery direction between said acceleration ducts and said first holes in connection with fluid passage with said second holes,
• a mask removably constrained to one or more of said support and said box and including a plurality of third holes centred with respect to said first holes, communicating with said second holes and configured to house part of said tubes and to allow, at the same time, the passage of said air or gas around said tubes,
• wherein
• said support comprises a housing configured to contain said box,
• said slit extends into said box from side to side so as to be in fluid passage connection with said second duct and configured to convey said air or gas from said second duct to said second holes,
• said mask comprises a seat configured to accommodate said box, and
• said seat is delimited by two side panels positioned on opposite sides with respect to said delivery direction and protruding parallel to said delivery direction, and
• said box comprises at least two fissures configured to each house a side panel.