1.The pressure screen basket is composed of a sieve perforated plate, an overflow bucket and a non-perforated plate. 2. There are many small holes distributed on the screen plate, and the vapor passes through the small holes from bottom to top, transfers heat and mass through the liquid layer on the tray, and then rises. 3. The liquid flows through the tray according to a certain route, and the liquid is held by the vapor with a stable flow rate, and flows through the overflow hopper to the non-porous plate (liquid receiving tray) of the next tray. 4. The thickness of the liquid layer is determined by the height of the inlet baffle and outlet baffle on the tray.