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What are the applications of graphite coolers in the condensation of furnace gas in the soda production?
- 2019-11-17-

In recent years, with the increasing market competition, the profits of various chemical companies have become lower and lower. Especially in the chlor-alkali industry, many companies have suffered losses for years. In the face of such a cruel reality, various chemical companies are also actively exploring and saving energy and reducing consumption, turning waste into treasure, and have achieved good results, saving a lot of production costs. At the same time, the state also strongly supports energy conservation and consumption reduction of various enterprises, turning waste into treasure. In the chlor-alkali industry, the caustic soda calcination section, the waste heat recovery of the furnace gas, and the reuse of condensate water in the furnace gas are an important way to save energy and reduce waste into treasure. Nowadays, the company's products include graphite plates, round block holes Graphite heat exchanger , round block type graphite preheater, round block type graphite falling film absorber, floating head tubular graphite type heat exchanger, tubular tubular graphite falling film absorber, rectangular block type graphite heat exchanger Heater, graphite heat exchanger in the kettle, two-in-one hydrogen chloride graphite synthesis furnace, three-in-one hydrochloric acid graphite synthesis furnace, round block type graphite sulfuric acid dilution cooler , trichloroacetaldehyde chlorination tower, graphite tower equipment and graphite There are hundreds of specifications of more than ten models such as chemical pumps, and various non-standard graphite equipment can be customized according to demand.

Prior to this, in the calcination section of the soda ash, the furnace gas condensation has been cooled and condensed in the form of a tower. The traditional tower material is mainly cast iron or carbon steel, and glass fiber reinforced plastic is used for anticorrosion. The cooling pipe is made of cast iron or carbon steel, and the anticorrosion is mainly based on the heat curing treatment of epoxy phenolic paint. Because there is a certain amount of H20 and NH3 in the furnace gas, the corrosion of the cooling pipe is strong. Although there is anti-corrosion treatment in the tube, due to the high temperature of the furnace gas and the corrosiveness, the anti-corrosion failure in the tube is still inevitable. After the anti-corrosion treatment of the cooling pipe, the heat transfer coefficient is greatly reduced, so the overall equipment design requires a large heat exchange area, so the investment is also relatively large. Although some manufacturers now use stainless steel tube furnace gas condensers to replace traditional condensing towers, the price of stainless steel is higher and the investment is higher. In addition, the furnace gas at higher temperatures corrodes stainless steel more seriously, especially to the tube sheet welding joints. Corrosion is extremely serious, and the service life cannot be guaranteed. Furthermore, because the furnace gas contains a large amount of lime dust, it will scale and scar on the stainless steel heat exchange tube wall. Accumulation over time not only affects the heat exchange effect, but also blocks the pipeline and increases air resistance. Due to the many limitations of the metal material itself, such as severe corrosion, severe tube plugging, expensive construction, and poor heat transfer efficiency, many experts and scholars have set their sights on non-metal materials, and graphite materials are the only thermally and electrically conductive properties. Very good non-metallic material, which has become a key choice. After years of cooperation between users and manufacturers, it has now become a mature product widely used in the soda ash industry, especially using graphite condensers in furnace gas condensation. obvious.

The company has formed long-term good cooperation with Jiangsu Meilan Chemical Co., Ltd., Sichuan Zhoulong Chemical Co., Ltd., Jiangsu Baju Pharmaceutical Co., Ltd., Nantong Nanhui Electronics Co., Ltd., and Jiangsu Zhoulong Chemical Co., Ltd. relationship. The cooperative graphite condenser has been replaced to replace the original stainless steel heat exchanger, which has solved the defects such as scaling, scarring and severe corrosion of stainless steel heat exchange tubes, and the heat exchange effect has also been significantly improved. It has been running well so far. The heat exchange areas of the four graphite furnace gas condensers are 337 square meters, 350 square meters, 580 square meters, and 330 square meters, respectively. These four graphite coolers are respectively used for the company's heating and heating and cold mother liquid heating. It is effectively used. At the same time, the furnace gas contains a large amount of water vapor, which can be reused after being condensed into water, which greatly saves production costs.

The graphite cooler produced by Golden Triangle Co., Ltd. uses the furnace gas in the tube side (inside the graphite tube) and the cold mother liquid or circulating water in the shell side (between the tubes). The graphite heat exchange equipment has excellent corrosion resistance and high thermal conductivity. As well as its small affinity for calcium and magnesium ions, it solves many of the disadvantages of the original metal heat exchanger equipment. The graphite furnace gas condenser can effectively cool, cool, and condense the calcining furnace gas. In the production of soda ash It has been approved by a large number of manufacturers, and its use will plan a new way for soda ash enterprises to make full use of low-grade thermal energy, save energy and reduce consumption. In the graphite furnace gas condenser, the graphite heat exchange tube and the tube sheet are connected by a highly elastic rubber sealing device, and the metal material and the non-metallic graphite tube bundle are organically connected and combined, so that each tube bundle can independently The thermal expansion and contraction completely eliminates the internal stress between the tube sheet and the graphite tube, which greatly reduces the probability of equipment damage and maintenance; this connection method avoids the pitting corrosion existing in the metal heat exchanger equipment and greatly reduces It reduces maintenance and repair costs, and can replace the single tube of the graphite heat exchanger, which greatly prolongs the service life of the equipment. It solves the problems of easy corrosion, leakage and short life of the stainless steel condenser in the past, and the heat exchange efficiency can be increased by more than 20% compared with the conventional stainless steel heat exchanger. The lower end of the graphite furnace gas condenser is provided with a gas-liquid separator, which can effectively collect the condensate, thereby realizing the reuse of the condensate. Graphite furnace gas condenser has broad promotion and application prospects in the industry, which is a strong guarantee for energy conservation and consumption reduction.

Impervious graphite has the following advantages: ① has a high degree of chemical stability. In addition to strong oxidizing acids and alkalis, it is resistant to most chemical media. ② Has extremely high thermal conductivity. The thermal conductivity of graphite is 100 ~ 110 W / m. K, whose thermal conductivity is similar to copper and aluminum, is 2.5 times more than ordinary carbon steel and 6 times more than stainless steel. ④ In terms of thermal stability, the use temperature of graphite can reach 180 ° C, and its thermal expansion coefficient is very small, about 0.4 to o. 45 × 10. 4m / K, not easily affected by temperature difference stress. ④Because the inner and outer walls of the graphite tube are very smooth, its absolute roughness is only 1/20 ~ 1/50 of the metal tube, and the resistance drop does not exceed 300 Pa; and graphite is a non-metal, which determines the "affinity" between the graphite tube and most media. "It is small, does not pollute the medium, and the wall of the pipe is not prone to fouling, thus expanding its application range.

Corrosion of equipment is a critical issue in the production of soda ash. Corrosion not only affects the quality of the product, but also affects the service life of the equipment and the consumption of metal materials. Therefore, research and reduction of corrosion in the production of soda ash is one of the major technical problems in the soda industry for a long time. Compared to metal and precious metal heat exchangers, graphite heat exchangers are an economical, efficient, and highly corrosion-resistant heat exchange equipment. , Pesticides, fertilizers and other chemical fields have been widely used. In recent years, in order to improve the heat exchange efficiency, recover low-grade thermal energy, reduce power consumption, and save equipment costs, the coal-alkali industry in China has also tried out graphite heat exchangers on many devices. Performance and energy saving have achieved good results, laying a foundation for the use of graphite heat exchangers in the production of combined alkali, and also created conditions for further reduction of energy consumption in combined alkali production.