Application of titanium in chemical industry

_ _ _ _ because titanium has excellent corrosion resistance, mechanical properties and processing properties, has been widely applied in many sectors of national economy. Particularly in the chemical production, instead of stainless steel with titanium, nickel base alloy and other rare metals as corrosion resistant material, the increase production, improve product quality, prolong the service life of equipment, reduce consumption, reduce energy consumption, reduce costs, to prevent the pollution, improve working conditions and enhance productivity, have very important sense. In recent years, our country chemical titanium in the constantly expanding the scope, quantity increases year by year, titanium has become the main chemical equipment anti-corrosion materials of. Titanium as a device for chemical corrosion structure material, has established its status, but also as an ideal material for chemical equipment titanium, also increasingly arouses the attention of project technology personnel. One, the chlor-alkali industry in chlor - alkali industry is an important basic raw material industry, its production and development has great influence on national economy. This is because the titanium on chloride ion corrosion resistance is superior to commonly used stainless steel and other non-ferrous metals. At present in the chlor-alkali industry widely used to manufacture titanium metal anode electrolyzer, ionic membrane electrolyzer, wet chlorine cooler, refined brine preheater, dechlorination tower, chlorine gas cooling and washing tower. The equipment of the main parts of the past use of non-metallic materials ( such as graphite, PVC), due to the non metal material mechanical properties, thermal stability and machining performance is not ideal, resulting in heavy equipment, large energy consumption, short service life, and affect the quality of products and environmental pollution. Therefore, our country since 70 time, begin with a metal anode electrolyzer and ion-exchange membrane electrolyzer electrolyzer instead of graphite, titanium wet chlorine cooler instead of graphite cooler, achieved good results. For example: titanium wet chlorine cooler application. Salt electrolytic production of caustic soda to cause high temperature and wet chlorine, temperature is generally 75 to 95 DEG C, after cooling and drying can be used. Our country salt electrolytic preparation of chlorine production, previously because of unreasonable cooling process or due to cooling the equipment corrosion of chlorine gas yield and quality, but also seriously polluted the environment. High temperature corrosion of titanium cooler of chlorine production, change in chlor - alkali industry producing chlorine production outlook. Titanium in high temperature and wet chlorine gas in the environment is very resistant to corrosion, titanium at room temperature of chlorine water, corrosion rate is 0.000565mm / A; at 80 degrees C of chlorine water, titanium corrosion rate of 0.00431mm / A; in 95% in wet chlorine gas under normal temperature, titanium corrosion rate of 0.00096mm / a. Many chlor-alkali plant uses titanium wet chlorine gas cooler, have been used for nearly 20 years, still intact. Two, soda ash soda industry is the most basic material of chemical industry, it is directly related to the development of the national economy. Soda ash production process, gas medium for NH3 and CO2, liquid medium for NaCl, NH4Cl, NH4HCO3 and Cl higher concentration solution, using carbon steel, cast iron material for carbonating reaction of carbonization tower tubular cooler, cooler, thermal liquid crystal external cooling device, such as the main equipment, are not resistant to corrosion, corrosion serious leakage, the service life of not more than three years. 1975-1977 years, Tianjin Soda Plant and Dalian Chemical Industry Company plant were made of titanium application demonstration work, carbonation tower cooling tube diameter of 63 x 2mm, titanium plate, titanium heat exchanger external cooling device, titanium pump, CO2, Ti-6Al-4V alloy turbine compressor rotor impeller and so the application effect is very good, it is the industry for using titanium technology and the new three an annual output of 600000 tons of soda ash factory played a model role. For example: some soda plant of ammonia condenser distillation tower top application of pure titanium tube instead of cast iron pipe. Ammonia condenser soda production process, the distillation distilled ammonia condensing device, which is composed of two cast iron cooling box, each box of diameter 2.5m, high 1.2m, the original has a 63 x 6 x 2986mm cast iron tube 214, two total 428 boxes of root. Inside and outside the tube with thermosetting phenolic varnish anti-corrosive, tube medium for NH3, CO2, H2O vapor, temperature of about 95 DEG c.. The tube away NH4Cl mother liquor, and the outer tube of medium to exchange heat. Under this condition, cast iron pipe corrosion is serious, use a year that is part of the pipe corrosion perforation, 2 years has corrosion damage is serious, stop using. For the solution of ammonia condenser cast iron pipe cast iron pipe serious corrosion problems, will be completely replaced by the TA2 titanium tube, specifications for the diameter of 60 x 2 x 3010mm, titanium tube and cast iron flower plate using O type rubber sealing ring. This is the soda ash industry in China the first distillation tower cooling tubules using pure titanium tube. Put into use for more than two years, has drawn tube macroscopic examination, did not find the expected corrosion, service life of up to 20 years, 10 times longer than cast iron pipe. Because the titanium tube corrosion, heat transfer efficiency to maintain good ( cast iron pipe in 3 years an overhaul period, the heat transfer efficiency of prophase, metaphase spreads, the late failure ), NH4Cl mother liquor pipe preheating heat recovery, improve liquor into the distillation column temperature, can save a large quantity of steam, obvious economic benefit.