【Major Chemical Equipment】035 – China’s first set of multi-stage centrifugal high-pressure ammonium methoxide pumps

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The past decade has been a period of rapid development for China’s chemical industry, marked by the emergence of many new processes, products, and equipment. There has also been significant progress in China’s chemical processing equipment, which has contributed to the swift advancement of the petrochemical sector. Here, we have compiled some of the achievements and breakthroughs made by Chinese equipment manufacturers in terms of larger-scale production and increased use of domestic equipment. We invite everyone to share their insights and discuss these topics together; let’s cheer for Made in China and support the development of chemical processing equipment! *********************************** Currently, new fertilizer production projects in our country are mainly of the 5080 scale (500,000 tons of synthetic ammonia per year and 800,000 tons of urea per year), while earlier fertilizer projects were mostly of the 3052 scale. The selection of high-pressure ammonium pump and high-pressure liquid ammonia pump is primarily influenced by the plant’s production capacity and the pressure in the synthesis tower. Reciprocating piston pumps are commonly used in medium and small urea production plants, while high-speed partial-flow pumps and multi-stage centrifugal pumps are often used in large urea plants; currently, multi-stage centrifugal pumps receive the best market feedback. The disadvantages of reciprocating piston pumps are low flow rate under applicable operating conditions, complex structure, many wear-prone components, easy leakage in packing seals, heavy maintenance requirements, high operating costs, and a short fault-free operation time. There is a certain gap in meeting the requirements for high flow rates, long operation cycles, high safety levels, and environmental sustainability; as a result, it is rarely used in fertilizer production projects these days. The disadvantage of high-speed partial-flow pumps is that they are suitable for operating conditions with low flow rates, high head, and high rotational speeds, typically ranging from 14,000 to 22,000 rpm. As a result, the materials used in such pumps as well as the requirements for their manufacturing are very high; similar high demands exist for the seals and impellers used in conjunction with them. Pumps have many failure points, are difficult to inspect and maintain, and incur high operating as well as inspection and maintenance costs. Multi-stage centrifugal pumps (see Figures 1 and 2) fall between the two; they are relatively easier to manufacture, have better sealing mechanisms, and are more reliable. Multiple sets of multi-stage centrifugal pumps have been put into use in China, and they offer a better design and supporting solutions compared to those from imported brands. In 2010, Dalian Deep Blue Pump Co., Ltd. signed a supply and sales contract as well as a technical agreement with Shandong Ruixing Group Co., Ltd. to carry out the design and production of China’s first set of multi-stage centrifugal high-pressure ammonium hydroxide pumps and high-pressure liquid ammonia pumps. It was successfully driven on-site by the user in 2012, with all performance parameters meeting the user’s requirements. The equipment features easy operation, a long fault-free operating time, few failure points, and stable performance, earning it unanimous praise from users. As of 2019, there were over 6 sets of multi-stage centrifugal high-pressure ammonium hydroxide pumps and high-pressure liquid ammonia pump units that were independently developed, designed, and manufactured in China, of which more than 3 sets were in operation (see Figures 3 and 4).