How does viscosity affect pumping?

How does viscosity affect pumping?

As the viscosity increases, the pump performance has to be adjusted to account for the additional resistance to shear. Typically there is a small reduction in flow, a more significant reduction in head or pressure, and a substantial increase in power draw.

How is the flow rate of a liquid related to its viscosity?

The relation is called Poiseuille’s law, which describes the smooth flow of a fluid along a tube. The flow rate F is proportional to the pressure drop Δp=p1–p2 divided by R , the resistance to flow. Thus, the flow rate is inversely proportional to the viscosity.

How does a pump curve change with viscosity?

The higher viscosity of a liquid actually reduces the amount of slip and increases the volumetric efficiency of a positive displacement pump. The curves in Image 7 illustrate how capacity of positive displacement pumps vary with speed (pressure constant), pressure (speed constant) and viscosity.

What is the maximum viscosity for a centrifugal pump?

Centrifugal pumps are usually capable of transferring liquids with viscosities lower than 520–760 cSt. The viscosity can be increased to 1000 cSt by using specific impellers. However, for a pump to be economically efficient, the maximum recommended liquid viscosity is 150 cSt [1].

Which type of pump is used for high viscous fluid pumping?

reciprocating pumps
Now reciprocating pumps typically pump highly viscous fluids like concrete and heavy oils, and serve in special applications that demand low flow rates against high resistance. Reciprocating hand pumps were widely used to pump water from wells.

What is the maximum viscosity for a peristaltic pump?

about 2000 cps
Factors which influence the flow rates Viscosity: The maximum viscosity a peristaltic pump can handle is about 2000 cps. The higher the viscosity, the lower the flow rate. It is recommended to use a tubing with a wall thickness of 2.4 mm or larger and a larger inner diameter than if you were pumping water.

Which impeller is good for low viscosity liquid?

In many cases, a hydrofoil impeller blade is well-suited for lower viscosities, while an axial flow or turbine pitched blade is better for mixing highly viscous substances. Furthermore, density of a substance is an important characteristic related to viscosity.

Which pump is used for high viscous fluid?

EDDY Pump
The EDDY Pump makes a great choice for pumping highly viscous material. The EDDY Pump’s geometric rotor acts as a mixer on thixotropic materials and provides a shear thinning effect enabling the pump to move high viscosity liquids much more efficiently than other pumps.

Which is better for high viscosity liquid pumps?

Delivery rate depends on the velocity of the fluid. F 550 S-50/21 with three-phase motor With higher viscosities delivery rate will be lower, depending on the velocity of the fluid. Recommended for transferring Thin to highly viscous, even pasty, still free flowing substances.

How much viscosity can a rotary pump handle?

Typically, reciprocating power pumps can handle fluid viscosities of 5,000 SSU and air operated piston reciprocating pumps can handle fluid viscosities of 1 million SSU. In selected technologies and applications, rotary PD pumps can also handle liquid from water to viscous liquids, but they find more typical application on viscous fluid.

How to correct centrifugal pump performance from water to viscous?

Prior to computer programs, there were basically three methods to correct a centrifugal pump’s performance from water to viscous. The A.J. Stepanoff model was viable at the best efficiency point (BEP) for head and flow but reliability and validity diminished with increased departure from the BEP.

How does the viscosity of the fluid affect the friction?

When pumping fluid, the more viscous the liquid the more friction will occur. The resistance (friction) is due to the shear stress properties of the fluid and the wall surface of the pipe/pump. Note that the smother the pump and pipe surfaces/walls are the less effect the viscous fluid friction will have.