Thread Content
Currently, for domestic non-metallic desulfurization pumps, in addition to corundum ceramics, the pump bodies are generally constructed with a steel lining over ultra-high molecular weight polyethylene; the thickness of this lining ranges from 8 to 20 mm. These pumps utilize patented plastic-lining technology, and compared to other similar pumps, they offer advantages such as excellent resistance to thermal deformation of the lining layer, resistance to cracking, prevention of delamination, and the ability to operate at high temperatures. They meet the requirements of being corrosion- and wear-resistant, capable of multiple functions, and suitable for use with both acidic and alkaline liquids and slurries. They are primarily used for transporting corrosive liquids. Desulfurization pumps operate under harsh conditions; in the wet desulfurization process, problems such as scaling, blockage, corrosion, and wear are very severe for these devices. In particular, corrosion and erosion of desulfurization pumps are significant issues, as the slurry at the bottom of the desulfurization tower contains a large amount of solid particles, mainly fly ash and desulfurization medium particles. The particle size ranges from 0 to 400 μm, with over 90% falling within the 20 to 60 μm range, and the concentration is between 5% and 28% (on a mass basis). These solid particles have strong abrasive properties. At present, to address the issues of corrosion and wear resistance in pumps used for desulfurization across various industries in China, there are mainly three technical solutions: 1. Using steel-lined materials combined with wear-resistant plastics. To optimize certain desulfurization pumps, manufacturers employ lining techniques to reduce costs, using polymers such as polypropylene, polytetrafluoroethylene, and other wear-resistant engineering plastics. This pump extends the service life to a certain extent, but it also has potential drawbacks, such as the issue of repairing worn linings and limitations on the conditions under which repairs can be carried out. 2. Improved metal materials: Traditional solutions involve raising the grade of the material in order to address design flaws and corrosion caused by the surrounding medium. For example, the material used in desulfurization pumps of type A49 is actually white cast iron with a high chromium content; it is similar to Cr30 material, with a chromium content of around 28.5%. This is a material developed by pump manufacturers based on their experience and knowledge of the environmental conditions. The increase in material costs ultimately exacerbates the imbalance between supply and demand, reduces competitiveness and resilience, and leads to the waste of numerous limited resources. 3. Application technologies of polymer materials: Sorei Industrial’s polymer repair materials possess excellent bonding properties, as well as resistance to corrosion, wear, erosion, cavitation, and provide a mirror-like surface effect (which significantly reduces friction under high-speed turbulence). These materials not only address the common problems associated with pumps but also play a crucial role in extending the pump’s service life, ensuring long-term stability in its performance, and improving its efficiency. It not only enables effective control of manufacturing costs, but also features excellent performance and a long service life; furthermore, it helps users extend the procurement cycle and reduce production costs. Such as corrosion and erosion in desulfurization pumps used in thermal power generation: the medium is limestone slurry with a pH of 5.5–6 and a temperature of 60°C; the pump model used is Shijiazhuang Industrial Pump 800DT, with a rotation speed of 1480 r/min, leading to erosion and corrosion of the impeller, pump casing, and protective plates.