Paper Machine Vacuum Pumps
Paper machines need a large, steady vacuum across the forming, press and felt (couch/pick-up) sections, pulling water out of the web. The air is wet and carries fibre and fines.
A liquid ring vacuum pump is the standard choice: the water ring seals against air leakage, tolerates the moisture and fibre without damage, and runs reliably for years with low maintenance.
We supply single-stage liquid ring pumps (2BE1, 2BV, NEV2) and, where deeper vacuum is needed, two-stage units (TXV).
Suction boxes, couch rolls and felt conditioning elements may operate at different vacuum levels, so the system is normally divided into headers or pump groups rather than throttling every point from one deep-vacuum source. The pump must be rated for the combined air leakage, water vapour and dewatering load at the actual operating pressure.
An inlet separator or knock-out vessel keeps large slugs of white water and fibre out of the pump, while a discharge separator recovers the seal water. Cast iron is suitable for neutral service; 304 or 316 stainless wetted parts are considered when chlorides, bleaching chemicals or process-water chemistry make corrosion a concern. Packing is simple to maintain, whereas a mechanical seal is preferred when visible leakage must be minimized.
Seal-water temperature is part of the duty point: warmer water has a higher vapour pressure and can reduce useful capacity, especially toward the deeper end of the operating range. Check the available cooling-water temperature, separator drainage and anti-cavitation provision together, and include flushing access where fibre can settle in low points.
Pumps for this duty: