Vertical packaging machine and method for packaging products

A vertical packaging machine for packaging products in a bag, said machine comprising:

• a forming unit extending along a vertical longitudinal axis, and comprising a hollow inner tube with an inner cavity configured to be crossed by a product to be packaged and a hollow outer tube surrounding the hollow inner tube, said hollow inner and outer tubes being arranged to define an annular passage within a gap between the inner tube and the outer tube, said inner cavity and said annular passage being configured to be put in communication at a bottom of the forming unit during packaging;
• dispensing means configured to dispense a film to the forming unit;
• encircling means configured to face longitudinal ends of the film along the forming unit;
• longitudinal sealing means configured to seal the faced longitudinal ends of the film to form a continuous tube around the hollow outer tube of the forming unit;
• transversal sealing and cutting means configured to transversally seal and cut the continuous film;
• a hopper in communication with inner cavity of the hollow inner tube;
• a connection cone arranged between said hopper and said forming unit and configured to receive the product from the hopper, said connection cone having a lateral wall;
• at least one gas ejector provided on said lateral wall of the connection cone, said at least one gas ejector being connected to a gas supply unit and positioned to eject a gas flow towards the inner tube of the forming unit and;
• at least one gas extraction conduit connecting the annular passage with a gas extraction unit configured to extract the gas flow entering the annular passage from the bottom of the forming unit
• a discharge member placed downstream said at least one gas ejector and upstream the inner tube of the forming unit with respect to a delivery direction of the product, wherein said discharge member is provided with at least one discharging vent, said discharge member being arranged in communication with the hollow inner tube and being configured to allow a fraction of the ejected gas flow present in the inner cavity and which is not extracted by the gas extraction unit through the annular passage to escape the hollow inner tube through the at least one discharging vent.