Structure of Backwash Device for Screen Changer of Extruder

　　The backwashing device of the net screen changer of extruder includes the main body with an axial hollow through hole, and the inlet and outlet ports connected with the hollow through hole are symmetrically arranged at the position of the radial center line of the main body, and the main ports parallel to the main axis and communicated with the outlet are arranged at one side of the outlet of the inner wall of the hollow through hole; and the two main axes of the main body of the net screen changer are arranged at the two axes of the main body. The end face is located at one side of the outlet, and each side of the outlet has an exhaust passage connected with the hollow through hole; the filter carrier inserted in the main hollow through hole and matched with it dynamically is provided with a screen room on both sides of the radial central line of the filter carrier, a filter screen is installed in the net room, and a screen chamber runner is set up at the bottom of the net room. There is a backwashing runner connected with the upper main channel set by the main body of the screen changer on the bottom side of the two mesh chambers of the filter carrier. The backwashing runner and the backwashing runner set in the same mesh chamber on the filter carrier are parallel to each other, and they form an interworking structure through slots.

　　When the center line of the filter carrier coincides with the center line of the main body, the inlet and outlet of the main body are connected with the two mesh chambers, and the flow channels and backwashing flow channels of each mesh chamber are connected with the main channel of the main body.