Refining: Screw pumps are increasingly used in refinery applications due to their tolerance of high viscosity and temperature as well as their ability to handle vapors and light hydrocarbons. Typical applications include vacuum tower bottoms, coker charge, flare knockout, loading/unloading, and asphalt. Leistritz Flare Knockout Pumps with a superior gas tolerant design that will not vapor lock, are often used as replacements for bad acting vertical centrifugal pumps challenged by flashing product. Re-engineered Pump offer a drop-in replacement solution for high maintenance or obsolete pumps. Combining a custom fabricated casing with a standard pump cartridge (single seal, single bearing), the re-engineered pump enables upgrades without the need to modify piping or driver. Leistritz refinery pumps can be supplied with VFD control to optimize energy use and are fully compliant with API 676 III Ed. standards. Double seals and magnetic drive as well as various material options are available for the most efficient and low maintenance operations.
Terminals & Asphalt Services: A growing number of installations of two and three screw pumps in pipelines and bulk terminals can be explained by the increasing use of heavy oils all around the world. The screw pumps can safely handle the heavy oil with lower temperature than a centrifugal pump and their capacity is independent of density and back -pressure. By using screw pumps also costly diluents blending can be eliminated or sharply reduced. Heavy asphalt and bitumen are successfully pumped using Leistritz two and five screw pumps in terminals, blending facilities and with barges and rail tankers. With VFD speed control the pump speed can be controlled and thereby the flow of the pump independent of viscosity and back pressure. This feature is used when blending different grades of asphalt and when stripping tanks and suction lines in barges and rail tankers.
Trends In Asphalt Pumping Video