Reasons for the Decline in Efficiency of Single-Stage Split Double-Suction Pumps

Single-stage split double-suction centrifugal pumps, also known as single-stage double-suction split volute pumps, are significantly affected by the viscosity of the medium they handle. Increased viscosity leads to a reduction in both the head curve and the flow rate under ideal conditions. Below are the key factors contributing to the decline in efficiency of these pumps:

Mechanical and Volume Losses:

The single-stage horizontal split double-suction centrifugal pump has been used for a long time, and the resistance will increase when the mechanical wear and leakage occur, and the mechanical loss and volume loss will decrease.

Surface Erosion:

After being flushed by the water flow, the inner wall of the split pump flow channel and the impeller passing through the water surface become uneven, the friction resistance coefficient of the flow channel in the pump will increase, and the water flow rate in the pump will increase, and the head loss will increase. The hydraulic efficiency will decrease.

Water Quality Impact:

Due to water quality, the pump body volume will become smaller, the pumping volume will decrease, the flow channel will become rough due to wear, the head loss will increase, and the hydraulic efficiency will decrease.

Cavitation and Structural Defects:

During processing, cavitation, casting defects, corrosion and wear will occur, causing cracks and holes in the flow channel of the single-stage double-suction pump, and vortices will form when the water flows, which will cause energy loss. Indirectly lead to a decrease in the efficiency of the centrifugal pump.

Cavitation on Impeller Surface:

Cavitation occurs on the impeller surface. Negative pressure is generated when the blade back water surface is running. When the pressure is lower than the specified value, cavitation and honeycomb surface will be generated. Under the action of corrosion, cavitation will occur in the single-stage double-suction centrifugal pump. According to the analysis of the operating conditions of the single-stage horizontal split double-suction centrifugal pump for many years, the main reason affecting the efficiency, operation and service life of the split pump is mostly cavitation.

In summary, addressing these factors is crucial for maintaining the efficiency and longevity of single-stage split double-suction centrifugal pumps.