Disc Pumps Become More Efficient When Pumping High-Viscocity Chemicals

Unique in design, the disc pump bridges performance gaps of convential pumps in several applications, especially when transferring chemical and petrochemical products.

Viscous Drag

The disc pump is not a centrifugal pump, positive displacement, gear or lobe pump. The pump harnesses the natural power of boundary layer and viscous drag. The boundary layer of fluid molecules collects and rotates with the discs. This creates a natural, protective buffer that separates the pump from the fluid. Through viscous drag, the fluid is pulled through the pump without impingement, in a smooth, laminar, non-turbulent flow. Disc pumps can handle high viscosities and require less horsepower than other pumps. The pumps deliver high product yields without shearing delicate solids. Apart from bearing lubrication and seal flush, maintenance is minimal during the pump's service life. Because of the viscous drag principle, the disc pump becomes more efficient as viscosity rises. While initial energy requirement may be the same as most conventional pumps, the disc pump uses less power when handling highly viscous material. This efficiency can save facilities high energy costs associated with pumping equipment.

Damage Control

The disc pump is optimized for the chemical industry because it minimizes contact between the pump and the material. This is a result of the viscous drag principle. Wear on the disc pump components is greatly reduced. In the case of delicate and shear-sensitive materials, damage to the product is virtually eliminated. The disc pump can adapt to highly viscous, high-solid and abrasive slurries, as well as sheer-sensitive and delicate fluids. At a paperboard manufacturing facility in Europe, a disc pump system handled lime slurry, black liquor soap, white liquor, coating waste and an abrasive, shear-senstive bentonite solution. The facility estimates the disc pump system has saved between US$10,000 and US$20,000 per pump per year by reducing unplanned maintenance or downtime. The disc pump features several capabilities that allow it to safely transfer corrosive chemicals, such as acids, sulfates, chlorinated hydrocarbons and other slurries. The pump can run dry and lacks radial loads or close tolerances. Leak prevention makes it ideal for both priming chamber and in-line processes. The types of harsh chemicals the disc pump can handle include shear-sensitive chemicals such as polymer emulsions, viscous fluids such as oil sludge and asphalt, and abrasive fluids such as drilling mud and sand slurries. Disc pumps should be manufacturered to the American Petroleum Institute (API) 610 Standard, 8th Edition, to ensure optimimal performance in high-temperature and high-pressure applications.