Synthetic Ammonia Process Technology Exchange Area [Daily Question 2009-03-12]

TH-847 corrosion-resistant coating is a thermosetting epoxy-amino coating developed by the Tianjin Institute for Comprehensive Utilization of Seawater Desalination. It boasts excellent corrosion and scale-inhibition properties, as well as various other advantages such as resistance to seawater, fresh water, and brackish water, wear resistance, impact resistance, and thermal conductivity. In 1989, the Office for Scientific Achievements organized a review meeting to assess the benefits of using TH-847 corrosion-resistant coating in the small nitrogen fertilizer industry, confirming the viability and reliability of this coating for protecting water heaters. Example of the internal protection application of coatings in industrial carbon steel water cooler equipment: Shanghai Fengxian Fertilizer Factory has invested a great deal of effort in coating processes, conducting repeated tests on factors such as the surface drying time of the coating, curing time, and curing temperature, in order to develop an effective set of procedural guidelines. In collaboration with Shanghai Chemical Machinery Factory No. 3, this factory jointly developed corrosion-resistant water heaters for heat exchange; the structure of the equipment was adjusted accordingly, and water heaters of various sizes, covering an area of 60–257 m2, were produced by applying the TH-847 coating. The Shanghai Wujing Chemical Plant, Jiading Fertilizer Plant, and Nanhuai Chemical Plant successively adopted carbon steel water coolers coated with TH-847 paint, achieving excellent economic and social benefits. Taking Nanhui Chemical Plant as an example, the service life of the water-cooling equipment was increased by 5 times, saving 200,000 yuan in costs and 28 tons of steel. Practical applications have shown that carbon steel water coolers coated with TH-847 paint generally see their service life increase by more than three times. Assuming that the service life of the water heater is extended to 2 years, a plant with an annual production capacity of 15,000 tons of synthetic ammonia can save 25 tons of steel per year, resulting in savings of over 200,000 yuan in investment costs. The Small Nitrogen Fertilizers Division of the Ministry of Chemical Industry has included this technology in the design specifications for corrosion protection of water-cooling equipment within the steam self-sufficiency and energy-saving projects. Water-cooled exchange equipment in the petrochemical industry accounts for about 40% of the total weight of the equipment used in petrochemical processes, and 20% of the investment costs associated with plant construction. Among this equipment, water coolers make up one-third of it. The losses resulting from shutdowns for repairs and replacements due to corrosion, perforations, and scaling blockages are quite substantial each year. The Production Department of Sinopec Corporation actively promoted the CH-784 corrosion-resistant coating (Tianjin Paint Factory’s 7910 coating). The Tianjin Institute for the Comprehensive Utilization of Seawater modified the CH-784 corrosion-resistant coating to develop the TH-847 corrosion-resistant coating for carbon steel water coolers. The petrochemical industry was the earliest and largest user of this technology; by the end of 1990, a total of 1,579 carbon steel water coolers had been coated across the industry, covering an area of approximately 355,000 square meters. Since May 1979, Daqing Petrochemical Complex has coated nearly 300 carbon steel water coolers, covering a total coating area of 36,000 m2 – accounting for 70% of the complex’s total carbon steel water coolers. The service life of these coolers has increased by 2 to 3 times on average, which has **reduced the heavy physical labor required for maintenance and cleaning, saved over 3 million yuan in repair costs, and spared more than 800 tons of steel**. The 54 water coolers in the 6 production units of the refinery at Anqing Petrochemical Complex utilize a combined protection method involving sacrificial anodes and coatings, and 8 years of practical use have shown that this approach extends the service life of the tube bundles. Since 1987, Cangzhou Refinery has coated 54 units, accounting for about 80% of the total number of carbon steel water coolers in the refinery, achieving excellent results in terms of corrosion and scale prevention. Shanghai Petrochemical Complex applied corrosion-resistant coatings to many large-scale water coolers for the 300,000-ton ethylene project; over a period of more than three years, more than 100 units were coated, covering an area of approximately 35,000 m2. To promote this technology, the Petrochemical Corporation formulated two provisional regulations in 1990: one on the painting techniques for protective coatings on water coolers and the other on the inspection of coating quality. These regulations provided detailed guidelines for design, construction, maintenance, on-site testing, and product quality acceptance.

I’m not very familiar with TH-847 paint; looking forward to the owner’s answer