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Instructions on the selection of phosphoric acid filters. Currently, there are three main types of domestic filtration equipment, including rotary disk filters, turning disk filters and belt filters. Among them, the domestic belt filter has a maximum area of 35m2 and is mainly used for small phosphoric acid plants. Turntable filter and rotating disk filter can be used in large phosphoric acid plants. At present, the maximum area of the flip-disk filter is 120m2 and the maximum area of the rotary-disk filter is 160m2, both of which have mature application experience. Large-scale phosphoric acid extraction plants abroad mainly use rotary disk filters. In China, due to the high price of imported rotary disk filters, turning disk filters were mainly used before 2001. After 2001, due to the successful development of domestic rotary disk filters, large-scale phosphoric acid plants constructed in recent years mainly use domestic rotary disk filters, such as Yunnan Furui Company (two 160m2 units), Sichuan Hongda Group (two 100m2 units), Sichuan Lomon Group (one 120m2 unit), Sichuan Xinyingfeng Third (80m2 one unit) Taiwan), Yunnan Xiangfeng Company (two 80m2 units), Yuntianhua Tianhu Chemical (two 100m2 units), etc. Yunnan Sanhuan Chemical Industry has selected four 160m2 units for its new 1.2 million-ton DAP (while all original phosphoric acid filtration uses turntable filters), and Yunnan Furui plans to use two more 160m2 turntable filters for its new 600,000-ton DAP. The comparison between rotary disk filter and flip disk filter is as follows: 1. Filter area: Since the rotary disk filter does not need to turn the disk, the rotation speed can be larger than that of the rotary disk filter. According to the filtration formula, Q=A·(ΔP·N·ψ/μ·R)1/2, the filtration capacity is proportional to the square root of the rotation speed. Therefore, the capacity of a rotating disk filter with the same area can be increased by 10 to 20% compared to a turning disk filter. In addition, due to the large slopes of the bottom of the filter plate and the suction pipe of the rotary disk filter (10° and 17°), the filtrate flows quickly, which is more conducive to increasing the rotation speed of the filter. However, the operating speed of the flip-plate filter is subject to certain limitations due to the characteristics of the filter plate flipping, which restricts the space for production growth. If we use a flip filter for our 110,000 tons P2O5/year output, the area must be greater than 110m2. According to the equipment sequence, only a 120m2 flip filter can be used. If you choose a rotary filter, you only need 100m2. 2. Investment: 1) Equipment investment a. Flip filter: According to the bidding results, the price of a 120m2 flip filter is 3.4 million yuan, excluding the installation fee. The installation fee is calculated as 6% of the total price of the equipment, totaling 200,000 yuan, totaling 3.6 million yuan. If you choose a 100 m2 flip filter, the price is 2.8 million yuan. If the installation fee is 168,000 yuan, the total is 2.968 million yuan. b. The price of a 100m2 rotary disk filter is 3.46 million yuan, including installation fees. 2) Civil construction investment a. Regardless of whether it is 100 m2 or 120 m2, the civil construction frame of the turntable filter will reach 22 * It has three floors of 22m, a construction area of 1452m2, and a civil construction investment of ~1.45 million yuan. b. 100m2 rotary disk filter civil frame 18 * It has three floors of 18m, a construction area of 972m2, and a civil construction investment of ~972,000 yuan. 3) Investment in auxiliary equipment. The flip filter needs to add a backflush vacuum pump, which costs ~50,000 yuan. 4) Total investment a. Rotary filter solution: 346+97.2=4.432 million yuan b. Turnover filter 120m2 plan: 360+145+5=5.1 million yuan 100 m2 plan: 296.8+145+5=4.468 million yuan 3. Comparison of operating costs: 1) The rotary disk filter saves a backflush vacuum pump, correspondingly saving power consumption of ~76,000 KWh, and saving electricity costs of 38,000 yuan/year. 2) Since the rotary disk filter does not have backflush, it can eliminate the acid backflush phenomenon and increase the phosphorus yield by 0.2-0.5%. Calculated at 0.2%, the annual recovery of P2O5 is 220t. Calculated at cost price, the annual income is increased by 390,000 yuan. 3) The rotary disk filter is designed to have 80% fewer rotating parts than the rotary disk filter, requiring less maintenance. It is said to be maintenance-free and can save maintenance costs of 20,000 yuan per year. 4) Since the turntable filter uses spiral cutting, the filter cloth is easily damaged. The filter cloth consumes 1/3 more than that of the turntable filter, which means an additional consumption of ~20,000 yuan of filter cloth per year. 5) The rotary disk filter can save the total annual operating costs compared with the turning disk filter.: 3.8＋39＋2-2＝418,000 yuan 4. In addition, the rotary disk filter has the following advantages: 1. It is more convenient and faster to replace the filter cloth ； 2. The operating environment is better. Yunnan Xinlong Company Technical Reform Headquarters 2005-11-12