Selection of centrifugal pumps in the marine engineering industry
The selection of centrifugal pumps in the marine engineering industry is a complex and critical process that requires consideration of multiple factors to ensure that the performance, reliability and durability of the pump meet the specific application requirements. The following are some suggestions for the selection of centrifugal pumps in the marine engineering industry:
1. Selection principles
Flow and head: Determine the required flow and head based on the specific needs of marine engineering. Flow represents the pump's delivery capacity, which is related to the impeller structure, size and speed; head represents the mechanical energy provided by the pump to a unit weight of fluid, which is also related to the flow, impeller structure, size and speed.
Material selection: Since seawater contains a large amount of salt and hard particles, corrosion-resistant and wear-resistant materials must be selected. Commonly used materials include stainless steel (such as 316 stainless steel or 316L stainless steel) and corrosion-resistant chromium alloys.
Shaft seal device: The function of the shaft seal is to prevent high-pressure liquid from leaking out of the gap along the inner edge of the pump casing, or external air from leaking into the pump. Commonly used shaft seal devices include packing seals and mechanical seals, which should be selected according to the specific working environment and requirements.
Operation cost: Including procurement costs, maintenance costs, energy costs, etc. When choosing, these factors should be considered comprehensively to select the pump with the best cost-effectiveness.
2. Common models
Split-center double-suction centrifugal pump: mainly used as electrolytic seawater circulation pump, seawater delivery pump, and can also be used to lower the groundwater level. It has the advantages of simple structure, easy installation, long service life, and more convenient maintenance of split-center structure. It is a widely used seawater pump type in marine engineering.
Multistage centrifugal pump: suitable for occasions where water sources need to be extracted at deep water levels, and can also be used for oil field water injection. Its design is more complicated than that of a single-stage centrifugal pump, with a large head range, suitable for seawater lifting conditions with high pressure and high head. Commonly used ones include DF-type corrosion-resistant multistage pumps and DFP-type self-balancing multistage pumps.
Centrifugal pump: It is a commonly used seawater delivery pump, concentrated brine pump and brine pump. According to the parameters, generally choose a multistage centrifugal pump if the head is greater than 150m or the outlet pressure is greater than 1.5Mpa. Considering that seawater delivery or brine pumps require corrosion-resistant materials, the pump body and flow-through components are usually made of 316L stainless steel or duplex steel.
3. Selection considerations
Understand the working environment: including the temperature, salinity, and particle content of seawater, which will affect the performance and life of the pump.
Consider maintenance convenience: Centrifugal pumps in marine engineering usually require regular maintenance and maintenance, so models and structures that are easy to maintain and maintain should be selected.
Choose well-known brands and manufacturers: The product quality of well-known brands and manufacturers is more guaranteed, and the after-sales service is more complete, which can reduce the risk and cost during use.
