Foam proportional mixing device

A foam proportional mixing device, wherein the foam proportional mixing device comprises:

• a Roots pump, the Roots pump comprising:
• a Roots pump housing, wherein a Roots pump cavity is formed in the Roots pump housing;
• a Roots pump inlet and a Roots pump outlet, wherein the Roots pump inlet and the Roots pump outlet are respectively arranged on two opposite sides of the Roots pump housing, and the Roots pump inlet and the Roots pump outlet are respectively in communication with the Roots pump cavity;
• a pair of rotors, the pair of rotors being located in the Roots pump cavity;
• and
• a fluid guide member, wherein the fluid guide member is arranged in the Roots pump inlet, and is configured to guide a fluid to flow to the pair of rotors and provide driving forces to the pair of rotors for rotating same in opposite directions from each other;
• and
• a gear pump, the gear pump comprising:
• a gear pump housing, wherein a gear pump cavity is formed in the gear pump housing, a gear pump inlet and a gear pump outlet are respectively provided on two opposite sides of the gear pump housing, and the gear pump outlet is in fluid communication with the Roots pump cavity;
• and
• a pair of gears, the pair of gears being located in the gear pump cavity;
• wherein the foam proportional mixing device is configured such that a rotor shaft of one rotor in the pair of rotors of the Roots pump is connected to a gear shaft of one gear in the pair of gears of the gear pump, so as to drive the one gear by means of the one rotor to rotate.