Dishwasher with residue disposal device and control method therefor

A dishwasher with a residue disposal device, comprising a housing and a liner, the liner being arranged in the housing, a spray assembly and a water collection assembly being arranged in the liner, the spray assembly being connected to the water collection assembly by means of a spray pipe, wherein the water collection assembly is provided with a drain hose, a residue disposal device is arranged on the drain hose and used for pumping and disposing residues, a three-way valve is arranged on a hose body of the drain hose and connected to the water collection assembly by means of a return pipe, and the three-way valve is controlled to form a closed water path from the water collection assembly to the residue disposal device in a first state, and is controlled to form a discharge water path from the water collection assembly to the residue disposal device and the drain hose in a second state;

• in a case where the closed water path is formed, the residue disposal device has a flow promotion effect to promote water flow in the closed water path to wash a water cup, in a case where the discharge water path is formed, the residue disposal device functions as a drain pump to promote disposed food residues to be discharged, the drain hose and the return pipe are connected to two sides of a bottom of the water collection assembly, the bottom of the water collection assembly is oblique, and an end, located at the drain hose, of the bottom of the water collection assembly is lower than an end, located at the return pipe, of the bottom of the water collection assembly, the residue disposal device comprises a shell and a rotating motor, an upper cavity and a lower cavity are arranged in the shell, the upper cavity is provided with a water inlet, the lower cavity is provided with a water outlet, a grinding assembly is arranged in the upper cavity, a drain impeller is arranged in the lower cavity, an output end of the rotating motor is connected to the grinding assembly and the drain impeller, the grinding assembly is used for cutting and grinding food residues, and the drain impeller is used for stirring a water flow, the grinding assembly comprises a blade assembly and a filter screen plate, the blade assembly is arranged on the filter screen plate and fixed to the output end of the rotating motor, a vertical circular wall plate is arranged on the filter screen plate, and the blade assembly fits the filter screen plate and the circular wall plate to grind the food residues, the blade assembly comprises L-shaped blades and cutting blades, sawteeth are arranged on edges of the L-shaped blades, each said L-shaped blade comprises first blade sections and a second blade section, the second blade section fits the filter screen plate, the first blade sections and the second blade section are connected with a right angle being formed therebetween such that the first blade sections are parallel to a circular side wall, each said cutting edge comprises third blade sections and a fourth blade section, and the third blade sections and the fourth blade section are connected with an angle greater than 90° being formed therebetween.