Screening machine for screening solid material

Screening machine (10) for screening solid materials, comprising:

• a screening box (12) shaped so as to have a plurality of perimeter walls (16, 17, 19, 21) and an upper wall (15),
• a plurality of screening surfaces (25) disposed inside said screening box (12) in order to make said solid materials to be screened flow,
• a plurality of passive type explosion anti-propagation devices (27), at least a first of which is disposed on said upper wall (15),
• wherein at least a second of said passive type anti-propagation devices (27) is associated with at least one of said perimeter walls (16, 17, 19, 21) by means of a connection device (38) that has both a function of decoupling with the inside of said screening box (12) and also a function of seal between two or more screening surfaces (25),
• wherein the anti-propagation devices (27) installed laterally, at a front, and/or at a rear, are associated with said respective connection device (38) in correspondence with a respective through aperture (36, 40),
• wherein each connection device (38) comprises a frame (39), able to be attached to one of said perimeter walls (16, 17, 19, 21), and a containing box (41) attached to said frame (39), on the opposite side with respect to that of attachment on said screening box (12), and associated during use with the respective anti-propagation device (27), and
• wherein said frame (39) is provided with a plurality of apertures (42) substantially having a height coordinated with a vertical distance of separation between said screening surfaces (25), and wherein inside said containing box (41) there are a plurality of plates (44) projecting from said frame (39) in correspondence with a lower edge of a respective one of said apertures (42).