The application of Sorey technology in pumps and fluid erosion/corrosion

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This post was last edited by Yamei on 2016-10-26 at 17:00. Keywords: pump casing erosion, repair of pump erosion, protection against pump corrosion, Sorex pump anti-corrosion measures, protection against erosion in pumps, fluid erosion and corrosion. China is a major country in terms of pump manufacturing and use, but its manufacturing techniques and pump design are relatively backward. According to data from relevant authoritative agencies and users, the performance indicators of pumps in terms of resistance to cavitation, corrosion, and erosion during operation are relatively low. Pumps, as general mechanical equipment, are widely used in various fields of the national economy. Pump bodies are generally made of castings, which have a rough surface. After operating for a period of time, the impact of water flow causes small pits to appear on the surface; these defects increase the flow resistance and thus raise the unnecessary work required by the pump. At the same time, destructive effects such as rusting, corrosion, abrasion, and cavitation cause the surfaces of the pump casing and impeller to become uneven, leading to an increase in the friction coefficient, a decline in pump efficiency, higher power consumption, and a shortened service life of the pump. Analysis of problems with pumps: The results of medium corrosion experiments show that the average corrosion rate of cast iron and carbon steel in seawater is 0.1–0.2 mm/year, with the penetration rate being 5–7 times the average corrosion rate. At the same time, the corrosion of steel in seawater is also a complex process involving various factors such as electrochemistry, physics, and chemistry; microorganisms are also one of the important factors affecting the corrosion of steel in seawater. Microorganisms that can cause material corrosion and degradation include aerobic and anaerobic bacteria, among which sulfate-reducing bacteria (SRB) are considered the primary bacteria associated with metal corrosion. Of course, other types of corrosion also exist, such as erosion corrosion, galvanic corrosion, etc. 2. Abrasive wear caused by material particles and sand: The continuous impact and abrasion exerted by these particles on the pump lead to severe wear of its components; in particular, wear problems are quite significant in the pump body, impeller, turbine blades, as well as at the pump’s inlet and outlet areas. Although many manufacturers currently use a large amount of high-hardness metals in material selection based on customer requirements, which does help to some extent, the cost is too high and the results are not ideal. During operation of an erosion pump, in certain local areas of its flow passage, when the static liquid pressure drops to the vaporization pressure of the liquid at that temperature, the liquid begins to vaporize there, generating a large amount of steam and forming bubbles. When the liquid containing these bubbles moves forward through the high-pressure areas inside the impeller, the high-pressure liquid surrounding the bubbles causes them to shrink rapidly until they burst. As the bubbles condense and burst, liquid particles fill the voids at high speeds; this creates a very strong water hammer effect, which strikes the metal surface at a high frequency. The impact stress can reach several hundred to several thousand atmospheres, while the impact frequency can be in the tens of thousands of times per second. Cavitation can destroy the protective film on the metal surface, accelerating the rate of corrosion ； Under the repeated action of such impact forces, the metal becomes fatigued and flakes off, resulting in small pits on the surface which can develop into a spongy structure; in severe cases, this can even lead to the breakdown of the wall thickness. The coexistence of factors such as corrosion, erosion wear, and cavitation in the pump body is a major cause of increased pump damage and higher energy consumption. As fluid transport equipment in industrial centers, water pumps account for a significant portion of energy consumption, and this has become one of the main issues to be addressed in energy-saving efforts. Pumps are major consumers of energy; according to calculations by the General Machinery Industry Association, pumps account for around 20% of China’s total electricity consumption. Increasing the power efficiency of pumps is crucial for achieving energy savings and emission reductions. Comparison of solutions for pump body corrosion and erosion: 1. Traditional solutions are relatively slow in terms of developing and introducing new technological resources. The upgrading of many new products still relies on improving the quality of materials used (for example, to address issues such as cavitation, corrosion, or erosion in pumps, many pump manufacturers currently use expensive materials such as 304, 316S.S., 410, 410S.S. stainless steels, nickel alloys, or bronze). This leads to an increasing imbalance between supply and demand, a decline in competitiveness and risk resistance, and waste of limited resources. Companies typically use spare equipment to store parts in order to address various issues that may arise with the pumps. 2. Sorei Industrial Technology utilizes high-performance polymer nanopolymer materials with excellent cost-effectiveness; this not only helps to control manufacturing costs effectively, but also ensures superior performance and a longer service life. It also enables users to extend the procurement cycle and reduce production costs. The repair technique using polymer nanopolymer materials involves spraying SOLID polymer material on the flow surfaces of pumps and their impellers, thereby creating a hydrodynamically smooth surface. This ultra-smooth coating provides a surface finish 20 times better than that of polished stainless steel. Such a highly smooth surface reduces fluid stratification within the pump, thereby minimizing turbulence and reducing volumetric and hydraulic losses. This leads to lower power consumption and a reduction in flow resistance, ultimately improving the hydraulic efficiency of the pump by 3%-10%. Furthermore, the Sore 8000 series polymer materials are essentially polymers; the dense molecular structure of their coating prevents contact between media such as air and water and the base material of the pump impeller, thereby minimizing electrochemical corrosion and rusting to the greatest extent possible ； It possesses chemical resistance, which can improve the pump’s corrosion resistance and **enhance the pump’s ability to withstand erosion and corrosion. Depending on the different media and fluids, as well as factors such as pressure and temperature in the field conditions at the flow sites, various Soray 8000 series polymer materials can be selected for repair and protection purposes. You can contact Sorei, where professional technical engineers will select the most suitable materials for repair and protection based on your on-site conditions. Case study on on-site repair of pump body corrosion and erosion: In the enterprise’s gas production unit in 2015, the ring area at the pump inlet of the sewage pumps suffered from frequent wear during operation, which severely affected their normal functioning. Sorei Industry provided scientific analysis and solutions for the corrosion, erosion, and wear of industrial sewage pumps, and the two parties have engaged in active cooperation on this matter. The relevant data is as follows: Sewage pump model: Hot water 600S32T ； Rotation speed: 980r/min ； Material: Cast steel ； Medium: wastewater, turbidity 600 NTU ； Temperature: 70-80℃ ； Cold water 600S46 ； Rotation speed: 980r/min ； Material: Cast steel ； Medium: Sewage water ； Temperature: 30-40℃ ； The sealing ring area of the pump body is severely worn.