Method and equipment for intermittently recycling waste liquid of chlorosilane during polycrystalline silicon production

The invention discloses a method for intermittently recycling chlorosilane in discharged waste liquid in a washing tower during polycrystalline silicon production, and the method the following steps of: intermittently charging a chlorosilane waste liquid produced in polycrystalline silicon production into an evaporation device at different places, evaporating trichlorosilane and silicon tetrachloride with lower boiling point into a gas state when the temperature of the evaporation device is controlled at 120-180DEG C and the pressure of the evaporation device is controlled at 0.1-0.6MPa, and charging the gaseous trichlorosilane and silicon tetrachloride into a rectifying tower so as to be purified and recycled. The invention further provides the evaporation device used in the method. The invention has the beneficial effects that the method is simple in process, the process condition is easy to realize, and the method is convenient to operate; and the treatment difficulty of the chlorosilane waste liquid during polycrystalline silicon production in the process of production can be improved, the discharge quantity of exhaust liquor can be mainly reduced, the waste of the chlorosilane can be reduced, the treatment load of an alkali liquor pond can be reduced, the environment pollution problem can be remitted, the labor quantity can be reduced, the production cost can be reduced, the complete recycle of the chlorosilane can be realized, and the phenomenon of equipment blockage can be avoided.