SU1681888A1 - Water filtering method - Google Patents

Abstract

The invention relates to the field of water purification on slow filters and improves the efficiency of the process. Layers of granular loadings of heavy and light filtering materials are successively placed into the filter housing, then the layers of lightweight filter material are mixed with the upper part of the heavy filtering material, an upward flow of water is fed to the upper part of the mixed layer and the lightweight grain size layer is lifted 0.5-3.0 mm. At the same time, crushed claydite is used as a light material, the layers are mixed and the light material layer is separated out by means of an upward flow using a hydraulic ripper buried in the load, and the ratio of the height of the mixed load layer and the light load layer extracted from it is 1: 0.1-0.5. 3 hp f-ly, 2 tab.

Description

The invention relates to the field of water purification by filtration, in particular to the technology of water treatment at sewage treatment plants with slow filters.

The aim of the invention is to increase the efficiency of the process.

Example.On the installation of filtration-technological analysis, representing the model of a slow filter, a layer of crushed clay with a size of 0.25-0.5 mm is placed on a layer of sand with fractions of 0.25-0.5 mm. A hydraulic ripper poured into the load at a flow rate of 1.1-1.4 l / s in one nozzle is used to mix the load, and then crushed expanded clay 30 cm thick at a flow rate of 0.3-0 is separated into the upper layer. , 8 l / s in one hydraulic ripper nozzles. Through the installation, water from the Aksai river is filtered from top to bottom: the turbidity is 90-100 mg / l, color up to 36.6 degrees. pH

8.45. The filtration rate is kept constant at 0.4 m / h. The quality of the filtrate meets the requirements of GOST, 1 Then, similar experiments were carried out after the extraction of fractions 0.5-1.0 in the upper layer of crushed expanded clay; 1.0-2.0; 3.0-6.0 mm.

Criteria for evaluating the effectiveness of the filtration process are the duration of the filter cycle, filter performance and heat capacity. Technological indicators of the load operation are presented in Table. one.

From the data given in table. As can be seen from Fig. 1, the highest filter capacity and duration of the filter cycle is achieved with a grain size of crushed expanded clay in a dedicated layer of 0.5-3.0 mm. This is explained as follows. With a grain size of crushed claydite, in the layer of loading of 0.25-0.5 mm selected at the top, the bulk of the contamination is delayed by

00 00 00

loading surface, a film is formed, which leads to a rapid increase in pressure loss, which dramatically reduces the duration of the filter cycle and, consequently, performance.

The decrease in filter performance with a grain size of crushed expanded clay in an isolated layer of 3.0–6.0 mm is due to the fact that with a sand size of 0.25– 0.5 mm, the crushed clay grain of 3.0–6 size should be separated from the mixed layer. , 0 mm is not possible because the hydraulic size of crushed expanded clay with a particle size of 3.0-6.0 mm is larger than the hydraulic size of quartz sand.

In this case, a mixed load is formed, the porosity of which is less than the porosity of the load with a grain size of crushed expanded clay in a dedicated layer of 0.5-3.0 mm.

PRI mme R 2. At the installation of filtration and technological analysis, which represents a model of a slow filter, a layer of crushed expanded clay with a particle size of 0.5-3.0 mm is placed on a layer of sand with a ratio of 1: 1 layers, with a total loading thickness of 80 cm. A hydraulic ripper with a water flow rate of 1.1-1.4 l / s in one nozzle produces mixing of the load to a depth of 60 cm. immersing the hydraulic ripper to a depth of 2 cm at a flow rate of 0.3-0.8 l / s in one nozzle, which is corresponds to the ratio of the thick layers of the mixed load and the crushed expanded clay layer extracted from it 1: 0.03. Through the installation, the water of the Aksai river is filtered in the downward direction with the following composition: turbidity of 90-100 mg / l, color up to 36.6 degrees, pH 8.45. The filtration rate is kept constant at 0.4 m / g. The quality of the filtrate meets the requirements of GOST. Then, similar experiments were carried out when the load of crushed expanded clay with a thickness of 7, 10, 20, 30, 40 cm was selected upwards, which corresponds to the ratio of the thicknesses of the layers of the mixed load and the crushed expanded clay layer extracted from it 1: 0.1; 1: 0.166 ;; 1.0.33; 1: 0.5; 1: 0.66.

The benchmark for comparison was a slow filter model loaded with a 1: 1 ratio mixed load of crushed expanded clay with a grain size of 0.5-6.0 mm and silica sand of 0.25-0.5 mm grain size, and a filter model loaded with a two-layer load of crushed expanded clay and quartz sand similar

size with expanded clay layers 30 cm, sand 50 cm,

The criterion for the effectiveness of filtering zaruzok serve duration

filter cycle, filter capacity, the amount of water required to flush the load.

Technological indicators of work downloads are presented in Table. 2

0 As can be seen from the data given in table. 2, with an increase in the ratio of the thicknesses of the layers of the mixed load and the layer of crushed expanded clay extracted from it, the duration

5 of the filter cycle. However, to regenerate the load with a thickness of 40 cm of crushed expanded clay, which corresponds to the ratio of loading thicknesses 1; 0.66, a larger percentage of wash water is needed, therefore

0, the filter performance is reduced compared to loading with a ratio of the said layers equal to 1: 0.5. When isolating a mixed layer of crushed expanded clay with a thickness of 2 cm (1: 0.03 ratio)

5, the filter capacity is increased slightly by 1.1-1.2 times in comparison with the known filtering methods with mixed and two-layer loading. Optimal conditions for implementation

0 of the proposed method is observed at a ratio of loading layers equal to 1: 0.1-0.5, when the filter capacity is increased 1.6-3.5 times in comparison with the known filtering methods.

Claims (4)

1. A method of filtering water, including sequential laying of layers of granular load of heavy and light filter material, mixing 0 layers of upward flow of water, passing the treated water through the charge and the subsequent regeneration of the load by the wash water flow, characterized in that, in order to increase the efficiency 5, a layer of light filter material is mixed with the upper part of the layer of the material, and an upward flow of water is fed to the top of the mixed layer and the loading layer is separated to the top. 0 from lightweight material with a grain size of 0.5-3.0 mm, 2. A method according to claim 1, characterized in that, for example, crushed expanded clay is used as a light material. 5 3. The way pop. 1, characterized in that the mixing of the layers and the isolation of the layer of light material is carried out by feeding an upward flow of water using a hydraulic ripper recessed into the load. 4. The method according to paragraphs. 1-3, that is, so that the ratio of the height of the mixed loading layer and the light loading layer extracted from it is 1: 0.1 0.5 Table 1 8.0 9.0 10.0 table 2 13 14,016,028,028,0