Air mixer for compressed air foam fire-extinguishing system and fire-extinguishing system

An air mixer for a compressed air foam (CAF) fire-extinguishing system, comprising a liquid inlet pipe (1), an air inlet pipe (2), a straight pipe (3), a first tapered pipe (4), a second tapered pipe (5), an energy storage mechanism (6), and a cushion mechanism (7), wherein the first tapered pipe (4) is a three-way pipe;

• the air inlet pipe (2), the first tapered pipe (4), the straight pipe (3), and the second tapered pipe (5) are sequentially connected according to an airflow direction;
• the liquid inlet pipe (1), the first tapered pipe (4), the straight pipe (3), and the second tapered pipe (5) are sequentially connected according to a foam concentrate direction;
• and small-diameter ends of the first tapered pipe (4) and the second tapered pipe (5) are respectively connected to an inlet end and an outlet end of the straight pipe (3);
• the energy storage mechanism (6) comprises a blind pipe (61), a piston (62), and an energy storage spring (63);
• an inlet of the blind pipe (61) is sealingly fixed to an opening in a wall of the air inlet pipe (2);
• a cavity of the blind pipe (61) communicates with a cavity of the air inlet pipe (2);
• the piston (62) is positioned and limited in the blind pipe (61);
• and the energy storage spring (63) is limited between the piston (62) and a blind end of the blind pipe (61);
• the cushion mechanism (7) comprises a positioning ring (71), a guide post (72), a guide sleeve (73), and a damper spring (74);
• the positioning ring (71) is fixed on the guide post (72);
• the damper spring (74) is sleeved on the guide post (72);
• one end of the guide post (72) is limited in the guide sleeve (73), and is in sliding fit with the guide sleeve (73);
• the damper spring (74) is limited between the positioning ring (71) and the guide sleeve (73);
• and a position of the guide sleeve (73) is fixed;
• and
• wherein two cushion mechanisms (7) are provided and respectively positioned at a same side or different sides of the straight pipe (3);
• a porous plate (31) is further fixed in the straight pipe (3);
• the air mixer further comprises a housing (8);
• the straight pipe (3), the first tapered pipe (4), the second tapered pipe (5), the energy storage mechanism (6), and the two cushion mechanisms (7) are positioned in the housing (8);
• an inlet end of each of the liquid inlet pipe (1) and the air inlet pipe (2) is led out from the housing (8) to connect an external device;
• and the outlet end of the straight pipe (3) is led out from the housing (8) to connect an external device;
• and
• the guide sleeve (73) is fixed in the housing (8).