The use of titanium tubes in large PTA installations has become a trend
Regardless of whether it is from the scale of production capacity, the level of equipment, or from the perspective of technology and product competitiveness, after more than 10 years of rapid development and industrial upgrading, China's PTA industry has won a global competitive advantage. In 2018, China's PTA's effective production capacity reached 45.79 million tons, the output was 40.8 million tons, and the self-sufficiency rate reached 99.8%. Large-scale and integrated PTA production equipment, leading technology, efficient operation and low energy consumption have also become the distinctive features of the current operation of the industry.
The PTA production process includes complex chemical processes such as mixing, hydrogen production, reaction, evaporation, condensation, extraction, separation, and drying, as well as liquid phase transportation, gas phase transportation, gas-liquid mixed phase transportation, solid-liquid slurry transportation, and solid-state Phase powder transportation and other processes. Its production process is also accompanied by outstanding features such as high temperature, high pressure, and strong corrosiveness of process media.
Affected by process and production characteristics, in recent years, titanium materials, high-performance corrosion-resistant titanium plates and tubes have been used in PTA devices in the international market. Because titanium alloy has strong corrosion resistance, and corrosion resistance is far better than stainless steel. It has particularly strong resistance to pitting, acid corrosion, and stress corrosion. . At the same time, it has high strength, tensile strength is 686MPa ~ 1176MPa, density is generally 4.5 g / cm3, only about 60% of steel. In PTA devices, titanium tubes are mainly used for heat exchanger tubes of condensers and heat exchangers, with high reliability and long life. In Norway, Japan and other countries, titanium alloy materials are widely used in related equipment in the petroleum field.
The use of titanium alloy materials for domestic PTA devices has been a recent issue, but titanium alloy materials are mainly imported. Investigating the reasons, on the one hand, the technology package of China's PTA device mainly adopts foreign technologies such as INVISTA technology and BP technology, so the titanium alloy seamless pipe used in the device is logically matched with foreign materials. On the other hand, domestic PTA companies had not been able to buy domestically produced titanium welded pipes for a time because of the lack of good titanium belts in China, and high quality titanium welded pipes were welded with good titanium belts. Finally, a realistic situation is formed, and seamless titanium tubes are mostly used in domestic PTA devices.
The focus of using titanium welded pipes in PTA devices is to solve the problem of corrosion resistance. The structure of large-scale equipment is very complicated, so many pipes are brought together. If there is any corrosion of the pipeline, rust and other conditions, the manufacturer must stop for maintenance, which will not only increase the operating cost, but also affect the normal production of the company in the peak season. In addition, there is a problem of 'secondary pollution'. Therefore, in recent years, the use of titanium alloy materials in domestic PTA devices has highlighted the urgency. "
At the same time, from the current trend, the number of companies using titanium titanium pipes in PTA devices is gradually increasing. "The production of slotted titanium pipes is more environmentally friendly, belongs to clean manufacturing and green manufacturing, and is more convenient and economical."
The products have successfully entered the "national team" and become the core suppliers of strategic markets such as large aircraft, nuclear power, and ships in China. The application of titanium alloys in naval submarines and other fields can reduce weight and improve corrosion resistance. From the previous year, the application of titanium materials in submarines and aircraft carriers in China was led by the company. The aircraft engine components, skeletons and other parts use a large amount of titanium alloys. About 50% of the titanium materials currently used in domestic large aircraft come from Xiangtou Jintian. At the same time, it is also the only Chinese supplier of high-performance titanium belts and tubes in the international market in the fields of energy, seawater desalination, and marine engineering.