Analysis of the method of calculating high resistance drainage of rapid filters

Summary

The methods of calculating high resistance drainage distribution systems for rapid filters are considered. In the practice of designing filtration plants in Russia several approaches to the structural concept of drainages that provide for equilibrium distribution of wash water in area have been worked out. It is shown that the method proposed by VNII VODGEO is the most substantiated; therefore it seems advisable to restore the recommendations on the use of this method in the practice of designing filtration plants in the regulatory documents. The analysis of the practical use of different approaches to the most useful method of calculating high resistance drainages for rapid filters shows the need to take into account a whole complex of indicators in these calculations. The most important among them is the indicator of drainage open ratio as well as assumed values of original flow rate of wash water in collectors (channels) and branches that determine the value of recovered head.

Key words

rapid filter , drainage-distribution system , wash uniformity , drainage open ratio , backwash loss

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UDC 628.315.3.004.1

Ulchenko V. M.

Wastewater Aftertreatment on Granular Bed Filters

Summary

Problems of the wastewater aftertreatment on granular filters of different design are described. Advantages of Ecopolymer drainage systems at reconstruction of these filters are shown. On the basis of generalization of its firsthand knowledge the Ecopolymer Group of Companies in the course of designing of wastewater aftertreatment uses rapid filters with descending filtration, air-water washing and rinse water low discharge system consisting of Ecopolymer sand-catching chutes and stream-guiding protuberances. Filters are equipped with the Ecopolymer drainage-distribution system consisting of drainage filters and Ecopolymer aerators. Conditions required for successful operation of wastewater aftertreatment rapid filters are defined. Results of operation of such filters designed by the Ecopolymer Company are presented.

Key words

granular media , rapid filter , drainage-distribution system , wastewater aftertreatment , filtration cycle

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UDC 628.16.067.1

Filatov A. I.

On some specific features of calculating drainage-distribution systems of large area rapid filters

Summary

Two main methods of calculating drainage-distribution systems for uniform washing of rapid filters are known: as regards the relation of the total surface area of drainage slots to the filter area and as regards the so-called relation of the total surface area of drainage slots to the cross-sectional area of the collecting manifold. The second method seems to be more consistent since it provides for the direct link between the values of the recoverable dynamic pressure in the pipes and the total head loss in the drainage required for the uniform filter wash. When using this method for calculating large area filters it is suggested to take into consideration the head loss at the sudden expansion of the cross section of the wash water flow at the head of the central (side) canal.

Key words

rapid filter , drainage-distribution system , pressure losses , wash uniformity , central canal

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UDC 628.16.067.1.004.1

Ulchenko V. M., Tregub Yu. A., Vilkova E. Kh., Ostroushko Yu. V.

Experience in Operation of Ecopolymer Drainage-Distribution Systems at the WesternFiltration Station Luganskvoda

Summary

Results of the operation of Ecopolymerdrainage-distribution systems in rapid filters of water treatment facilities are presented. In the course of operation of filters with media, small sand fractions are concentrated gradually in the upper layer leading to rapid reduction in filtration rate in the beginning of a filtration cycle. After the upper layer of filtration material has been removed the main process operational parameters became normal. It is shown that the necessity of removing the upper layer of filtration material can be evaluated according to the character of the curve of fluctuations of a maximum filtration rate. The filter material preparation technique for filters with water washing equipped with the Ecopolymer drainage-distribution systems is given. The research shows that they ensure a high evenness of washing and filtrate collection along the whole filter surface without any supporting layers, and their operation characteristics are higher than of fissure drainage that makes it possible to use sand of required granulometric composition.

Key words

rapid filter , filter bed , drainage-distribution system , filtration rate , duration of filtration cycle

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UDC 628.16.067.3.004.67

Rodin N. V., Troshkova E. A., Grigoruk A. N., Bychkov D. A.

Reconstruction of rapid sand filters at the Velizhany water treatment facilities of Tumen

Summary

The city of Tumen is supplied with drinking water from two water sources – surface and underground. The complex of Metelevskii water intake and treatment facilities with a capacity of 150 thousand m3/day was built in 1981. The Velizhany water treatment facilities with a capacity of 128 thousand m3/day of drinking water were built in 1970-ies. The need for not simply repair but for the reconstruction of the facilities with improving the reliability of the treatment process was stipulated by the growing water deficiency in a rapidly developing city as well as by the lack of capacity reserve. The experience of upgrading rapid filters at the municipal water treatment facilities with the use of advanced drainage-distribution systems is presented. The drainage-distribution systems before and after rapid filters reconstruction are described; their basic parameters are given. The experience of retrofitting Triton drainage system in experimental filter No. 13 of the Velizhany water treatment plant is described. For the comparative evaluation and determination of the rapid filter maximum operational life control back washing of the filter media in filters No. 13 and 4 were carried out. In 2013 pilot tests of possible using Culligan Italiana S.p.A. filter media for removing manganese from the water of the Velizhany intake deep wells were carried out. The upgrade of the Metelevskii water intake rapid filters provided for required capacity of the purification facilities and water quality under the forced working conditions inter alia by means of the right selection and design of the drainage-distribution system. The experience of reconstructing filters at the Tumen water treatment facilities was used in the process of developing the relevant section of the «ROSVODOKANAL» Group technical policy.

Key words

water treatment , rapid filter , drainage-distribution system , aeration , filter layer , control back washing

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