Chemical Industry

Application of Cascade ring
Refinery vacuum distillation column：

Refinery vacuum distillation tower: Dg50 carbon steel step ring is used to replace the original three-layer circular bubble cap tray in the oil vapor condensation section (φ4.2m) at the top of the vacuum distillation tower in the refinery, and the height of the packing layer is 1.36m. After the replacement, the pressure drop is 3mmHg, which is only 11.5% of the original, and the heat output of the filler is 220,000 to 320,000 kcal/h·m3. The temperature at the top of the tower can be adjusted sensitively and can be stable at 60-80°C. The vacuum degree of the evaporation layer is much higher than before, which can save 4.6 tons of steam per hour.
Absorption tower and regeneration tower of decarbonization system: the design capacity of hydrogen production workshop of a nylon factory is 1000m3 (standard)/h. The absorption tower and regeneration tower of its decarbonization system were originally filled with 35*35*4 porcelain Raschig rings. After switching to carbon steel and polypropylene stepped rings, the production capacity reached 1307m3 (standard)/h, exceeding the original maximum level of 1267m3 (standard)/h; the pressure drop of the absorption tower was only 0.02-0.03MPa, which is about the same as the Raschig ring. The absorption and regeneration capacity is significantly improved, and the mass transfer coefficient is increased by about 50%; the operation is stable and the quality is good.
Application in the synthetic ammonia decarburization unit of a medium-sized fertilizer plant: In a certain plant, ceramic Raschig rings were used for the second decarburization, which had low mass transfer efficiency, and was easily broken and blocked the heat exchanger; the CO2 content in the secondary decarburization gas often exceeded the standard, resulting in methane Overheating will affect catalyst life and increase hydrogen consumption. Since the step ring was adopted for the secondary decarbonization and secondary regeneration in 1984, under the high load of 180 tons of synthetic ammonia per day, the CO2 content in the secondary decarbonized gas is still less than 0.1%. The ceramic Raschig ring of the secondary decarburization absorption tower was changed to a metal stepped ring, and the packing support grid plate and the liquid distribution plate were renovated at the same time; the ceramic Raschig ring of the secondary decarburization regeneration tower was changed to metal and polypropylene steps Ring, and achieved obvious results.

Technical effect and economic benefit after transformation:

① Completely eliminate the factor of overtemperature of the methanation catalyst caused by the excessive CO2 content in the secondary decarbonization gas;
② It was determined that the resistance of the secondary decarburization tower was reduced from 0.05MPa to 0.03MPa; the processing gas volume was increased from the originally designed 14800m3 (standard)/h to 17690m3 (standard)/h, and the production capacity was increased by about 20%; ③ Increased The purification degree of the secondary decarbonization gas is improved, and the CO2 content is reduced from 0.3 to 0.4% to 0.07 to 0.09%;
④ The regeneration tower solution does not need to be heated by steam, and the heat of the low-change process gas fully meets the heat required for the solution regeneration;
Based on the 0.2% reduction in CO2 content in the secondary decarbonization gas, under the existing capacity, the hydrogen consumed by the methanation reaction can increase the production of synthetic ammonia by 1.47t per day; at the same time, the exhaust gas of the synthetic ammonia can reduce the emission and increase the production of synthetic ammonia by 1.83t per day. , the total output of the two increased by 3.3t/d. If the annual production day is calculated as 290 days, the production will increase by 957t/a. Calculated at 300 yuan/ton, the annual output value can reach 287,100 yuan. After the renovation was completed, the investment amounted to 230,000 yuan, which was recovered in less than a year!
Ⅱ A factory is designed to produce 60,000 tons of synthetic ammonia and 110,000 tons of uric acid per year. The gas purification process is atmospheric pressure modified ADA desulfurization medium temperature shift, pressurized modified ADA desulfurization, glycine hot alkali decarbonization, copper ammonia washing, purification and decarbonization The production process is two-stage absorption and two-stage regeneration. The structure of the φ2200mm CO2 absorption tower is a 10m porcelain ring at the upper end and 25 double overflow sieve plates at the lower part.
Since the operation of the CO2 absorption tower, the operation of the CO2 absorption tower is often unstable, the pressure difference of the tower fluctuates, and even the liquid is blocked and liquid. Therefore, the CO2 absorption tower must be reformed. In 1982, the 38m3 porcelain Raschig ring (φ38*38*3, φ50*50*5, φ80*80*8) in the upper section of the originally designed absorption tower was changed to Dg60*30*3 ceramic step ring, and the tower structure and The relative modification of the sieve hole, weir height and liquid seal height of the tray increases the production capacity of the tower and improves the operation performance of the tower.
After the transformation, the gas volume of the CO2 absorption tower is increased from the original 22000-25000m3 (standard)/h to 26000-27000m3 (standard)/h (equivalent to the transformed gas volume entering the tower 32800-34100m3 (standard)/h), thereby increasing the production of synthetic ammonia to a new level. The CO2 purity of the reformed regeneration gas is also significantly improved.

Applications of Pall Rings
Application of Polypropylene Pall Rings in Tannin Extraction Desulfurization

A factory adopts tannin extract method for desulfurization. In the desulfurization tower with a tower diameter of φ6000mm, Dg76 polypropylene Pall rings with a packing layer height of 3.5m are used to replace the original designed wood grid packing. Production practice has proved that polypropylene Pall ring packing has the advantages of low resistance, corrosion resistance, not easy to break, not easy to block tower, and high desulfurization purification degree. The tower has been using this packing for N years, and the production has been stable and normal. Using this kind of filler to replace the wood grille filler can not only save a lot of wood, but also shorten the maintenance time by 4/5 and greatly reduce the labor intensity.
Fluoride absorption
In the acid production workshop of a fluoride salt factory, the use of polypropylene Pall ring packing has achieved good technical and economic results. In the past, the acid-making absorption tower of the factory used wood grid packing. Due to the crust on the surface of the wood grid, it had to be cleaned every three months, and the pressure drop was high, and the absorption effect was not good. The plant uses Dg50 polypropylene Pall ring packing to replace wood grid packing, and the height of packing bed is reduced from 4.8m to 2m and 1.2m. The average tower pressure drop is reduced from 80mmH2O to 35-40mmH2O. In the past, four 75KW fans were used, but now one 100KW fan is used, which saves power consumption.
The absorption efficiency of the tower is also improved. In the past, the fluorine content of the tail gas at the top of the tower was generally 0.07-0.08g/m3, and the average fluorine content after the transformation was 0.0435g/m3, which met the national emission standard.

Application of intalox saddle ring
Renovation of Regeneration Tower in Fertilizer Plant

A factory renovated the problems of serious mist entrainment and increased tower resistance at the outlet of the φ4000mm regeneration tower of the purification device. The original three-layer ceramic Raschig rings with a height of 6m per floor and a volume of 76m3 were all replaced with porcelain saddles of Dg38 and Dg25mm. Packing, and corresponding changes to the internal structure of the tower, such as improving the liquid distribution structure at the top, moving the gas-liquid distribution plate down 1.5m, and lengthening the gas riser.
After the transformation, the three-machine high-load (25000～26000m3[standard]/h) production, and the resistance of the regeneration tower dropped significantly, and the temperature of the regeneration gas outlet from the tower dropped from the original 100～102℃ to 95～99℃.
Renovation of Rectification Column and Absorption Column in Acetic Acid Production
The rectification tower of an acetic acid workshop in a calcium carbide factory was originally two towers of φ650mm and φ800mm, with Dg25 porcelain Raschig ring packing inside, and the two towers were connected in parallel, with a daily output of 106 tons of acetic acid. After being refitted to Dg25 porcelain saddle packing, only one tower of φ650mm can basically meet the production requirements, and the processing capacity has more than doubled.
The diameter of the acetic acid absorption tower in this plant is φ800mm. The original Dg25 porcelain Raschig ring packing was changed to Dg38 and Dg25 porcelain saddle packing, and the production capacity was increased by 15%.

Application of intalox saddlering
Renovation of Dewaxed Oil Phenol Refining Extractor in Refinery
A dewaxed oil phenol refining extraction tower in a refinery uses Dg50 metal ring saddle packing to replace the Dg50 porcelain stepped ring packing originally packed in the tower. Due to the thin wall of the metal packing, the operation is carried out under the same raw material and solution ratio as the old tower. After the transformation, the processing capacity can be increased by 15-20%, the yield can be increased by 1-2%, the average energy consumption of the device can be reduced by 3.5*104kcal/t, the solvent consumption can be reduced by 0.03kg/t, and the quality of the obtained refined oil has been improved.
Renovation of Phthalic Anhydride Refining Tower

The phthalic anhydride rectification tower in the phthalic anhydride workshop of a factory is a vacuum rectification tower with intermittent operation. The operating vacuum degree is 640-700mmHg, the tower diameter is φ700mm, the tower height is 11m, and the original Dg25 porcelain Raschig ring packing is 7m, divided into three parts. part. Then use Dg25 metal ring saddle packing instead of porcelain Raschig ring packing. After the transformation, the distillation time of each kettle is shortened from 24 hours to 20 hours, and the annual production capacity is increased from 6,500 tons to 8,000 tons. The rate of high-grade phthalic anhydride was increased from 60% before the transformation to 85%.

Applications of Conjugated Rings
Application in eucalyptus oil fractionation unit
The metal conjugated ring replaces the original copper wire mesh corrugated packing in a small eucalyptus oil fractionation device in a factory, which can overcome the phenomenon of frequent blockage. Due to the small pressure drop and stable operation, the annual cost of saving electricity is 15,000 yuan. , Since the non-ferrous metal copper material is replaced by carbon steel material (the filler needs to be replaced every six months in the past), the annual investment can be saved about 20,000 yuan, and its benefits are considerable.
Application in sulfuric acid production
The ceramic conjugated ring is used in the absorption tower of the small and medium-sized sulfuric acid plant with an annual output of 10,000t and 40,000t of sulfuric acid. Compared with the original stepped ring packing, the operation is stable, the gas pressure drop is small, and there will be no problems in long-term use (more than 3 years).
Application in aeration towers and exhaust gas discharge towers

The plastic conjugated ring is used in the aeration tower of the water supply equipment of a pharmaceutical factory, which can achieve stable operation, while in the absorption tower for the treatment of malodorous gas discharged from the dryer of a tobacco factory, the mass transfer effect is very good, and the odor is greatly reduced. .