Discussion on the localization of key valves in coal gasification processes

Thread Content

In coal chemical and coal-to-oil projects, gasification is the first step. The slag discharge systems of gasification units operate under very harsh conditions, which imposes strict requirements on valves; these valves need to have high wear resistance, resistance to erosion, as well as protection against scaling and scarring, along with the ability to shut off quickly. Especially for the slag locking valve, it is required to withstand high pressure and high temperature, deal with a medium (coal slag) that is very hard, operate frequently, open and close at high speeds, have good sealing performance, and exhibit high reliability. I. The valve brands currently used in coal chemical processing include: For oxygen: PEERIN, ARUCS, VELAN, EDWARD, Shanghai Kaiweixi, and China National Nuclear Corporation Su Valve. For coal slurry: German brands PEERIN and ARUCS, as well as the Dutch brand NELES. For slag locking valves: NELES, German brands PEERIN and ARUCS, Shanghai Hongsheng, and Kaiweixi. For slag water pipelines: Shanghai Hongsheng, Kaiweixi, NELES, Zhejiang Chaoda, and Lango. II. In some aspects of coal chemical processing, the valves used are now largely domestically produced. For example, for black water pipelines with operating temperatures ranging from 100 to 220°C and pressures from 0.01 to 0.5 Mpa, gate valves, stop valves, check valves, and metal hard-sealed ball valves of sizes 0.5”–12” and 150 Lb can meet the basic requirements, and all of these are now produced domestically.  For the circulating chill water pipelines, with operating temperatures of 150~220°C and pressures of 3.5~6.5 Mpa, valves of sizes 0.5”–12” such as 600Lb gate valves, stop valves, check valves, and metal-sealed ball valves can meet the basic requirements, and all of these valves are now domestically produced.  For coal gas pipelines, with operating temperatures of 150~220°C and pressures of 3.5~4.5 Mpa, 0.5”-28” 600Lb gate valves, stop valves, check valves, and metal hard-sealed ball valves can meet the basic requirements, and all of these products are now domestically produced.  For the quench water pipelines, with operating temperatures of 150~225°C and pressures of ~6.0 Mpa, 0.5”-28” 600Lb gate valves, stop valves, check valves, and metal hard-sealed ball valves can meet the basic requirements, and all of these components are now domestically produced. III. In the coal chemical industry, valves used in special operating conditions (especially those for pressurized transportation of pulverized coal, valves in oxygen pipelines, and valves in slag and water handling systems) are now being manufactured domestically. For processes such as Lurgi and GSP, key slag locking valves and hoppershut valves are produced by domestic manufacturers including Shanghai Kaisixi Valve Co., Ltd., Shanghai Hongsheng Special Valve Co., Ltd., Zhejiang Wuzhou Valve Co., Ltd., Chongqing Baishiyi Forging Valve Research Institute, and Zhejiang Chaoda Valve Co., Ltd. – a total of six valve manufacturers are involved in the domestic production of these slag locking valves. All of this data was compiled and edited by me; it was intended to be used as training material or a research paper for the company. In the future, more accurate and detailed information will be published for further discussion. If there are any shortcomings, please offer your advice. Haichuan is an excellent platform for mutual learning and discussion within our country; I hope everyone will speak up actively. Here are the ideas I suggest everyone discuss. Approach 1: Count the usage of key valves by manufacturers in various processes, as well as the situation regarding domestically produced valves. For example: Shanghai Coking Co., Ltd. uses 8 slag locking valves with a design pressure of 4.0; the imported valve brand is Neles from Finland, while the domestically produced valve brand is from Shanghai Kaisixi Valve Co., Ltd. Shandong Hualu Hengsheng uses 7 Argus valves, Shanghai Hongsheng Special Valve Manufacturing Co., Ltd. uses 4 valves from Yuanke Lunan, and Yuanke Guotai uses 3 valves. Approach 2: Examine the usage of each imported valve in the production processes of manufacturers in various processes. For example: Hao Lianghe and Nanhua Company use Perrin slag locking valves; their design features include a single valve seat and a fixed ball, with the valve ball and valve stem being connected together via a quadrilateral structure to transmit power ； Rigid seal; the valve seat is loaded by several cylindrical springs arranged in a circle. Application: The Perrin slag-locking valves used in Vaporizer A and Vaporizer B have cracked valve stems with some material missing, and the valve ball and valve seat show chipped areas as a result of erosion ； There was a leak in the slag locking valve of Vaporizer B; after disassembly and inspection, it was confirmed that the cemented carbide layers on the valve ball and valve seat had come off. Idea 3: The technical challenges that need to be addressed during the localization of various inlet valves, such as: slag locking valve: rapid shutdown ； Challenges such as scarring and scaling prevention; oxygen and hydrogen valves: materials that can withstand corrosion by high-pressure hydrogen sulfide as well as hydrogen embrittlement, with strict control over the levels of carbon, sulfur, and phosphorus ； Cleaning requirements, etc