Reduced-pressure concentration device for producing bis-imidazole

The vacuum concentration device comprises a concentration tank body, a mounting box is fixedly connected to the position, close to the center, of the top of the concentration tank body, a motor is fixedly connected to the position, close to the center, of the top of an inner cavity of the mounting box, and a first bearing is fixedly connected to the position, close to the center, of the top of the concentration tank body; a rotating shaft is arranged in an inner cavity of the first bearing in a penetrating mode, and through mutual cooperation of all the parts, medicine can be stirred, so that the medicine is evenly dispersed, the medicine is evenly heated, and the situation that the medicine is stacked, consequently, heating is uneven, and the concentration effect is affected is avoided; meanwhile, the stirring transverse rod and the stirring vertical rod can do internal and external reciprocating motion and up and down reciprocating motion while rotating, so that the stirring range is expanded, the stirring