The ZNZ series disc thickener is a vacuum multi-disc machine without water leg. It is applied for washing and thickening of various L.C. pulps. The product features its de-watering type similar to pump suction, so as to banish rigorous requirements on water leg installation by a traditional thickening machine. It exceptionally demands little on site height. Modified pulp thickener well functions the de-watering with negative pressure and wire-washing with positive pressure, which greatly promotes its washing efficiency and thickening effects of filtrate.